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Journal articles on the topic 'Serial dilution'

Author: Grafiati

Published: 4 June 2021

Last updated: 2 February 2022

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1

Keler, Cynthia, Tabitha Balutis, Kim Bergen, Bryanna Laudenslager, and Deanna Rubino. "Serial Dilution Simulation Lab." American Biology Teacher 72, no. 5 (May 1, 2010): 305–7. http://dx.doi.org/10.1525/abt.2010.72.5.9.

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Serial dilution is often a difficult concept for students to understand. In this short dry lab exercise, students perform serial dilutions using seed beads. This exercise helps students gain skill at performing dilutions without using reagents, bacterial cultures, or viral cultures, while being able to visualize the process.

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2

Arendrup, Maiken Cavling, Karin Meinike Jørgensen, Nicolien Hanemaaijer, and Paul E. Verweij. "ISO standard 20776-1 or serial 2-fold dilution for antifungal susceptibility plate preparation: that is the question!" Journal of Antimicrobial Chemotherapy 76, no. 7 (March 18, 2021): 1793–99. http://dx.doi.org/10.1093/jac/dkab088.

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Abstract Background Since the ISO standard 20776-1 and serial dilution procedures were compared in 2010 for fluconazole and itraconazole, several new antifungals that are hydrophobic and highly potent have been introduced. Objectives To investigate the impact of the number of tip changes during serial dilution, and ISO and serial dilution for nine antifungals. Methods EUCAST E.Def 7.3.2 with serial (0–10 tip changes) and ISO dilution. Candida parapsilosis ATCC 22019, Candida albicans ATCC 64548, C. albicans CNM CL-F8555, Candida krusei ATCC 6258, Aspergillus flavus ATCC 204304 and clinical isolates (n = 5) of C. albicans, Candida dubliniensis, Candida glabrata, C. krusei, A. flavus and Aspergillus terreus were included. GM MICs were compared for ISO and serial dilution and with QC values where available. Results Increasing the number of tip changes (0/1/2/10 times) during serial dilution for plate preparation increased the MICs 1 to >2 dilutions for amphotericin B, anidulafungin, micafungin, fluconazole, voriconazole and isavuconazole against C. albicans ATCC 64548 but only isavuconazole MICs against C. parapsilosis ATCC 22019 (3 dilutions). ISO and serial dilution (two tip changes) were compared for eight compounds and four Candida QC strains (352 MICs). Six/41 GM MIC pairs deviated with 1–1.8 dilution (14.6%). Comparing the GM MIC with the QC values, the ISO method GM MIC was closest to the target in 30.8%, the serial dilution in 34.6% and the methods identical in 34.6% of the cases. Finally, ISO and serial dilution MICs were compared for clinical isolates (920 MICs). Five/23 GM MIC pairs (21.7%) deviated 1.0–1.1 dilutions. Conclusions The ISO and serial dilution (two tip changes) method were in acceptable agreement and thus equally applicable for EUCAST testing.

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3

Blodgett, Robert J. "Planning a serial dilution test with multiple dilutions." Food Microbiology 26, no. 4 (June 2009): 421–24. http://dx.doi.org/10.1016/j.fm.2009.02.001.

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4

Paegel, Brian M., William H. Grover, Alison M. Skelley, Richard A. Mathies, and Gerald F. Joyce. "Microfluidic Serial Dilution Circuit." Analytical Chemistry 78, no. 21 (November 2006): 7522–27. http://dx.doi.org/10.1021/ac0608265.

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5

Ahrar, Siavash, Michelle Hwang, Philip N. Duncan, and Elliot E. Hui. "Microfluidic serial dilution ladder." Analyst 139, no. 1 (2014): 187–90. http://dx.doi.org/10.1039/c3an01710a.

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6

Harris, Cole O., and Stephanie L. Schweiker. "Optimizing production of serially diluted compounds and distribution to multiple targets." Journal of Automated Methods and Management in Chemistry 23, no. 6 (2001): 179–82. http://dx.doi.org/10.1155/s1463924601000220.

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The need for a multiple-target compound selectivity programme led to the establishment of a single robotic system that produces a compound's serial dilution and its distribution to multiple replicate assay plates. A Genesis RSP 150 integrated into a Zymate Laboratory Automation System XP produced the serial dilutions, and the subsequent replicate assay plates were produced quickly and accurately by an efficient use of the carousels and rapid plate. Currently, this process allows for the production of over 200 serial dilution assay plates in a workday.

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Flessland, Karen A., Helen R. Landicho, Kimberlee K. Borden, and Harry E. Prince. "Performance Characteristics of the PolyTiter Immunofluorescent Titration System for Determination of Antinuclear Antibody Endpoint Dilution." Clinical and Vaccine Immunology 9, no. 2 (March 2002): 329–32. http://dx.doi.org/10.1128/cdli.9.2.329-332.2002.

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ABSTRACT Conventional screening for circulating antinuclear antibodies (ANA) is generally performed by immunofluorescent (IF) microscopy with a 1:40 dilution of serum. Intensity of IF staining is then semiquantitated by using twofold serial dilutions, where the highest dilution in which staining intensity equals the endpoint control is expressed as an endpoint titer. The PolyTiter Immunofluorescent Titration system (Polymedco, Inc.) facilitates ANA-IF assay (IFA) testing by relating the intensity of IF staining to reference calibrators (defined in PolyTiter units), providing an endpoint titer directly from a 1:40 dilution. This study was conducted to assess the performance characteristics of the PolyTiter system. Two technologists each evaluated 10 replicates of three specimens and two controls on five sequential days. Endpoint dilution agreement (defined as ±2 dilutions) with the reference was 100% for all controls and for all specimens by one technologist. The second reader reported agreement of 98, 88, and 100% for the low, medium, and high specimens, respectively. Analysis of PolyTiter unit values yielded between-reader, between-run, and within-run precision coefficients of variation of less than 10%. The variance component in the lot-to-lot analysis was zero, indicating all of the variation was due to run-to-run differences. Overall endpoint dilution agreement between PolyTiter and serial dilution in the evaluation of 125 specimens at three sites was 90, 93, and 86%. Pattern identification with the PolyTiter was similar to that with serial dilution. The PolyTiter system demonstrates acceptable performance for routine ANA-IFA testing in the clinical laboratory.

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8

Gelman, Andrew, Ginger L. Chew, and Michael Shnaidman. "Bayesian Analysis of Serial Dilution Assays." Biometrics 60, no. 2 (June 2004): 407–17. http://dx.doi.org/10.1111/j.0006-341x.2004.00185.x.

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9

Ben-David, Avishai, and Charles E. Davidson. "Estimation method for serial dilution experiments." Journal of Microbiological Methods 107 (December 2014): 214–21. http://dx.doi.org/10.1016/j.mimet.2014.08.023.

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10

Gu, Guo-Yue, Yi-Wei Lee, Chih-Chung Chiang, and Ya-Tang Yang. "A nanoliter microfluidic serial dilution bioreactor." Biomicrofluidics 9, no. 4 (July 2015): 044126. http://dx.doi.org/10.1063/1.4929946.

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11

Bang, Hyunwoo, Sun Hee Lim, Young Kyung Lee, Seok Chung, Chanil Chung, Dong-Chul Han, and Jun Keun Chang. "Serial dilution microchip for cytotoxicity test." Journal of Micromechanics and Microengineering 14, no. 8 (June 18, 2004): 1165–70. http://dx.doi.org/10.1088/0960-1317/14/8/007.

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12

Blodgett, Robert J. "Serial dilution with a confirmation step." Food Microbiology 22, no. 6 (December 2005): 547–52. http://dx.doi.org/10.1016/j.fm.2004.11.017.

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13

Oliver, Kruger, Thorp, and Prescott. "Determination of the lowest dilution of aluminium acetate solution able to inhibit in vitro growth of organisms commonly found in chronic suppurative otitis media." Journal of Laryngology & Otology 114, no. 11 (November 2000): 830–31. http://dx.doi.org/10.1258/0022215001904365.

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Burow’s solution has been found to inhibit the in vitro growth of most commonly occurring bacteria found in the discharging ear. These organisms were inoculated onto appropriate agar plates that contained serial dilutions of aluminium acetate. Results show that the lowest dilution able to inhibit the growth of these organisms lies between a 1:80 and a 1:160 dilution of Burow’s solution.

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14

Wang, Anyang, Samaneh Moghadasi Boroujeni, Philip J. Schneider, Liam B. Christie, Kyle A. Mancuso, Stelios T. Andreadis, and Kwang W. Oh. "An Integrated Centrifugal Degassed PDMS-Based Microfluidic Device for Serial Dilution." Micromachines 12, no. 5 (April 23, 2021): 482. http://dx.doi.org/10.3390/mi12050482.

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We propose an integrated serial dilution generator utilizing centrifugal force with a degassed polydimethylsiloxane (PDMS) microfluidic device. Using gas-soluble PDMS as a centrifugal microfluidic device material, the sample can be dragged in any arbitrary direction using vacuum-driven force, as opposed to in a single direction, without adding further actuation components. The vacuum-driven force allows the device to avoid the formation of air bubbles and exhibit high tolerance in the surface condition. The device was then used for sample metering and sample transferring. In addition, centrifugal force was used for sample loading and sample mixing. In this study, a series of ten-fold serial dilutions ranging from 100 to 10−4 with about 8 μL in each chamber was achieved, while the serial dilution ratio and chamber volume could easily be altered by changing the geometrical designs of the device. As a proof of concept of our hybrid approach with the centrifugal and vacuum-driven forces, ten-fold serial dilutions of a cDNA (complementary DNA) sample were prepared using the device. Then, the diluted samples were collected by fine needles and subject to a quantitative polymerase chain reaction (qPCR), and the results were found to be in good agreement with those for samples prepared by manual pipetting.

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Vasilakis, Nikolaos, Konstantinos Papadimitriou, Hywel Morgan, and Themistoklis Prodromakis. "Modular Pressure and Flow Rate-Balanced Microfluidic Serial Dilution Networks for Miniaturised Point-of-Care Diagnostic Platforms." Sensors 19, no. 4 (February 21, 2019): 911. http://dx.doi.org/10.3390/s19040911.

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Fast, efficient and more importantly accurate serial dilution is a necessary requirement for most biochemical microfluidic-based quantitative diagnostic applications. Over the last two decades, a multitude of microfluidic devices has been proposed, each one demonstrating either a different type of dilution technique or complex system architecture based on various flow source and valving combinations. In this work, a novel serial dilution network architecture is demonstrated, implemented on two entirely different substrates for validation and performance characterisation. The single layer, stepwise serial diluter comprises an optimised microfluidic network, where identical dilution ratios per stage are ensured, either by applying equal pressure or equal flow rates at both inlets. The advantages of this serial diluter are twofold: Firstly, it is structured as a modular unit cell, simplifying the required fluid driving mechanism to a single source for both sample and buffer solution. Thus, this unit cell can be used as a fundamental microfluidic building block, forming multistage serial dilution cascades, once combined appropriately with itself or other similar unit cells. Secondly, the serial diluter can tolerate the inevitable flow source fluctuations, ensuring constant dilution ratios without the need to employ damping mechanisms, making it ideal for Point of Care (PoC) platforms. Proof-of-concept experiments with glucose have demonstrated good agreement between simulations and measurements, highlighting the validity of our serial diluter.

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Lee, Mei-Ling Ting, and G. A. Whitmore. "Statistical Inference for Serial Dilution Assay Data." Biometrics 55, no. 4 (December 1999): 1215–20. http://dx.doi.org/10.1111/j.0006-341x.1999.01215.x.

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17

Hamilton, Martin A., and Michael G. Rinaldi. "Descriptive statistical analyses of serial dilution data." Statistics in Medicine 7, no. 4 (April 1988): 535–44. http://dx.doi.org/10.1002/sim.4780070410.

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Bhattacharjee, Biddut, and Siva A. Vanapalli. "Electrocoalescence based serial dilution of microfluidic droplets." Biomicrofluidics 8, no. 4 (July 2014): 044111. http://dx.doi.org/10.1063/1.4891775.

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19

Blodgett, Robert J. "Finding Bounds Applied to Serial Dilution Experiments." Communications in Statistics - Simulation and Computation 29, no. 3 (January 2000): 793–99. http://dx.doi.org/10.1080/03610910008813640.

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20

Popa-Burke, Ioana, Brian Lupotsky, Joseph Boyer, William Gannon, Rob Hughes, Paul Kadwill, Donald Lyerly, et al. "Establishing Quality Assurance Criteria for Serial Dilution Operations on Liquid-Handling Equipment." Journal of Biomolecular Screening 14, no. 8 (August 12, 2009): 1017–30. http://dx.doi.org/10.1177/1087057109339938.

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Since the advent of high-throughput screening (HTS) in the early 1990s, parallel multichannel liquid handlers have become a mainstay in every drug discovery setting. Although several peer-reviewed publications have discussed methods and criteria for stamping multiwell copies, there is very little information about establishing a standard operating procedure (SOP) for standard (microliter-level) serial dilutions of compounds used in dose-response experiments. The authors discuss the 4 main criteria any serial dilution process must pass (accuracy, precision, fold dilution, and outliers) and the process for establishing thresholds for all of these values in a compound management or biological screening laboratory. The thresholds need to be both low enough to be acceptable from a biological potency variability perspective and high enough to allow the instruments to pass the quality assurance (QA) analysis on a regular basis. In this article, the authors suggest suitable thresholds arrived at by a variety of methods, including trend analysis of QA data, survey questionnaire from the main stakeholders (screening scientists, chemists), and published criteria for single-shot stamping. A mathematical analysis of the effect of threshold values on estimated XC50s was performed to ensure that the variability introduced by the serial dilution step is within acceptable overall variability limits.

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21

Salmon, Sarah A., Jeffrey L. Watts, and Robert J. Yancey. "In Vitro Activity of Ceftiofur and its Primary Metabolite, Desfuroylceftiofur, against Organisms of Veterinary Importance." Journal of Veterinary Diagnostic Investigation 8, no. 3 (July 1996): 332–36. http://dx.doi.org/10.1177/104063879600800309.

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Ceftiofur (XNL) and its primary metabolite, desfuroylceftiofur (DXNL), were evaluated for in vitro activity against 539 isolates from veterinary sources. Actinobacillus pleuropneumoniae, Pasteurella spp., Haemophilus somnus, Salmonella spp., Escherichia coli, staphylococci, and streptococci were tested. Overall, XNL and DXNL were equivalent in activity against the gram-negative organisms with all minimum inhibitory concentrations (MICs) within 1 serial dilution. Against the staphylococci, MIC differences of 2–3 serial dilutions were detected with an MIC90 for XNL and DXNL of 1.0 and 4.0–8.0 g/ml, respectively. Although the MIC90 obtained for Streptococcus suis for each compound was within 1 dilution, the MIC values against individual strains were 2–3 dilutions greater for DXNL than for XNL. The MICs obtained with the bovine and equine streptococci for DXNL (MIC90 = 0.03 g/ml) were 5 serial dilutions higher than those obtained for XNL (MIC90 £ 0.0019). Although DXNL was less active than XNL against the streptococci, these differences were not clinically important because both XNL and DXNL were highly active for these bacteria. Although these differences are of little importance with the streptococci, they may have important implications for susceptibility testing of the staphylococci. In conclusion, with the exception of the staphylococci, both XNL and DXNL were highly active against the organisms tested, with MICs for both compounds several fold lower than plasma levels achieved during dosing of XNL.

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22

Hassett, Daniel J., Eyad Alsabbagh, Kislay Parvatiyar, Michael L. Howell, Robert W. Wilmott, and Urs A. Ochsner. "A Protease-Resistant Catalase, KatA, Released upon Cell Lysis during Stationary Phase Is Essential for Aerobic Survival of a Pseudomonas aeruginosa oxyR Mutant at Low Cell Densities." Journal of Bacteriology 182, no. 16 (August 15, 2000): 4557–63. http://dx.doi.org/10.1128/jb.182.16.4557-4563.2000.

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ABSTRACT A Pseudomonas aeruginosa oxyR mutant was dramatically sensitive to H2O2, despite possessing wild-type catalase activity. Oxygen-dependent oxyR phenotypes also included an inability to survive aerobic serial dilution in Luria broth and to resist aminoglycosides. Plating the oxyR mutant after serial dilution in its own spent culture supernatant, which contained the major catalase KatA, or under anaerobic conditions allowed for survival. KatA was resistant to sodium dodecyl sulfate, proteinase K, pepsin, trypsin, chymotrypsin and the neutrophil protease cathepsin G. When provided in trans and expressed constitutively, the OxyR-regulated genes katB,ahpB, and ahpCF could not restore both the serial dilution defect and H2O2 resistance; only oxyR itself could do so. The aerobic dilution defect could be complemented, in part, by only ahpB andahpCF, suggesting that the latter gene products could possess a catalase-like activity. Aerobic Luria broth was found to generate ∼1.2 μM H2O2 min−1via autoxidation, a level sufficient to kill serially dilutedoxyR and oxyR katA bacteria and explain the molecular mechanism behind the aerobic serial dilution defect. Taken together, our results indicate that inactivation of OxyR rendersP. aeruginosa exquisitely sensitive to both H2O2 and aminoglycosides, which are clinically and environmentally important antimicrobials.

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Lin, Jie, Michael Manhart, and Ariel Amir. "Evolution of Microbial Growth Traits Under Serial Dilution." Genetics 215, no. 3 (May 4, 2020): 767–77. http://dx.doi.org/10.1534/genetics.120.303149.

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Selection of mutants in a microbial population depends on multiple cellular traits. In serial-dilution evolution experiments, three key traits are the lag time when transitioning from starvation to growth, the exponential growth rate, and the yield (number of cells per unit resource). Here, we investigate how these traits evolve in laboratory evolution experiments using a minimal model of population dynamics, where the only interaction between cells is competition for a single limiting resource. We find that the fixation probability of a beneficial mutation depends on a linear combination of its growth rate and lag time relative to its immediate ancestor, even under clonal interference. The relative selective pressure on growth rate and lag time is set by the dilution factor; a larger dilution factor favors the adaptation of growth rate over the adaptation of lag time. The model shows that yield, however, is under no direct selection. We also show how the adaptation speeds of growth and lag depend on experimental parameters and the underlying supply of mutations. Finally, we investigate the evolution of covariation between these traits across populations, which reveals that the population growth rate and lag time can evolve a nonzero correlation even if mutations have uncorrelated effects on the two traits. Altogether these results provide useful guidance to future experiments on microbial evolution.

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Buzas, Jeffrey S., Carrie G. Wager, and David M. Lansky. "Split-Plot Designs for Robotic Serial Dilution Assays." Biometrics 67, no. 4 (May 31, 2011): 1189–96. http://dx.doi.org/10.1111/j.1541-0420.2011.01617.x.

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Zelterman, Daniel, Alexander Tulupyev, Robert Heimer, and Nadia Abdala. "Statistical design for a small serial dilution series." Statistics in Medicine 29, no. 3 (November 26, 2009): 411–20. http://dx.doi.org/10.1002/sim.3774.

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26

Liao, Jason J. Z., and Fenghai Duan. "Calibrating the concentration from a serial dilution process." Journal of Chemometrics 20, no. 6-7 (June 2006): 294–301. http://dx.doi.org/10.1002/cem.1021.

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27

Stephan, Khaled, Patrick Pittet, Monique Sigaud, Louis Renaud, Olivier Vittori, Pierre Morin, Naim Ouaini, and Rosaria Ferrigno. "Amperometric quantification based on serial dilution microfluidic systems." Analyst 134, no. 3 (2009): 472–77. http://dx.doi.org/10.1039/b811629f.

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Won, Dong I. L. "Measurements of Endpoint Titers Based on the Fluorescence Intensity Trend in Anti-Nuclear Antibody Testing." Laboratory Medicine 51, no. 5 (December 24, 2019): 469–77. http://dx.doi.org/10.1093/labmed/lmz087.

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Abstract Background Automated systems for antinuclear antibody (ANA) testing provide endpoint titers that are predicted based on the fluorescence intensity (FI) value at a screening dilution (single-well titration [SWT]) showing frequent titration errors (more than plus or minus 1 dilution). Methods Line slope titration (LST) was based on the trend of FI values on dilutions. Three dilutions per specimen were prepared considering a patient’s previous titer or FI at the screening dilution. On the XY plot, with the reciprocal of dilution as the X-axis and FI value as the Y-axis, a fitted line was drawn to obtain the endpoint titers. Results The titration error rate (no. of errors/total no.) of LST using a regression line was lower than that of SWT (31/710 [4.4%] and 152/674 [22.6%], respectively; P < .000000001), with serial dilution as a reference. When comparing a regression line using 3 dilution points with a line using 2 dilution points, the error rate of the former was not significantly different from that of the latter (31/710 [4.4%] and 31/746 [4.2%], respectively; P = .842). Conclusions This LST method is useful as an accurate, cost-effective, and rapid approach to measure endpoint titers in routine ANA testing.

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De Simone, Nicole, and Ravi Sarode. "The Use of Activated Partial Thromboplastin Time As a Surrogate to Predict Residual FVIII Activity in the Bethesda Assay." Blood 128, no. 22 (December 2, 2016): 4962. http://dx.doi.org/10.1182/blood.v128.22.4962.4962.

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Abstract Introduction: Bethesda assays, used in the quantification of factor VIII inhibitors, are time and labor intensive. They are performed by mixing one part of normal pooled plasma (NPP) with an equal amount of serial dilutions of patient plasma in imadizole buffered saline (IBS), and incubating at 37°C for 2 hours. After the incubation time, most laboratories perform factor VIII (FVIII) activities on each tube. These results are divided by the activity resulted on the control (NPP+IBS) to obtain the percent residual activity. The dilution with a percent residual FVIII activity between 25-75% is then converted to a Bethesda Unit using the Bethesda graph. This value is multiplied by the dilution to calculate final Bethesda units/mL. We propose an alternative method, involving performing partial thromboplastin times (PTTs) on all dilution tubes and only performing FVIII activity testing on a limited number of tubes e.g. 2 tubes rather than all 10 tubes. The study below describes the methodology and provides data to show how the PTT can be used as a surrogate. Using PTTs may reduce cost per test by reducing the amount of FVIII deficient plasma used for FVIII activity testing, especially in the case of very high titer inhibitors. Methods: Serial dilutions of patient plasma with IBS are prepared to the 512 dilution (10 tubes) and incubated with an equal amount of NPP along with a control consisting of IBS and NPP. PTTs are run using Siemens Actin FSL reagent on the BCS coagulometer (Siemens) on all 10 tubes and the control. The tube with a resultant PTT within 5 seconds above the control is identified and then that tube, along with the next higher dilution, are tested for residual factor VIII activity (ACL TOP, Instrumentation Laboratory). These results are used to calculate the percent residual FVIII activity and Bethesda units/mL as described above. To support our hypothesis, we performed PTT and FVIII activities on all dilution tubes. Results: We performed 14 inhibitor assays on 9 patients. 44% (4/9) had congenital hemophilia A with an inhibitor and 56% had acquired hemophilia A. Table 1 shows results from dilution tubes that resulted in residual FVIII activities between 25-75%. The dilutions with residual activity closest to 50% were used in the final interpretation and are bolded. Using the 5 seconds above control PTT to identify dilutions to limit FVIII assays correlated with residual FVIII activities in 12 of the 14 samples tested (86%). Furthermore, this method identified the dilution with the residual FVIII activities closest to 50% in 10 of the 12 samples. Two samples demonstrated no correlation between PTT and FVIII activities. These samples had low titer inhibitors (<5 BU), which could have been predicted by the low PTTs in the first two dilutions. In these cases, serial FVIII activities were used in calculations. More data is needed to definitively say whether this methodology could not be used for low titer inhibitors. Conclusion: An alternative method, using PTT testing to perform targeted FVIII activity testing, may be used in the Bethesda Assay. Table Table. Disclosures Sarode: CSL Behring: Consultancy, Honoraria.

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Zacher, B. J., F. Moriconi, S. Bowden, R. Hammond, S. Louisirirotchanakul, P. Phisalprapa, T. Tanwandee, et al. "Multicenter Evaluation of the Elecsys Hepatitis B Surface Antigen Quantitative Assay." Clinical and Vaccine Immunology 18, no. 11 (August 31, 2011): 1943–50. http://dx.doi.org/10.1128/cvi.05122-11.

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ABSTRACTThe Elecsys hepatitis B surface antigen (HBsAg) II quantitative assay is a new quantitative electrochemiluminescence immunoassay which uses onboard dilution and a simple algorithm to determine HBsAg levels expressed in international units (IU)/ml (standardized against the World Health Organization [WHO] Second International Standard). This study evaluated its performance using routine serum samples from a wide range of HBsAg carriers and patients with chronic hepatitis B (CHB). HBsAg levels were measured in serum samples collected independently by five centers in Europe, Australia, and Asia. Serial dilution analyses were performed to assess the recommended dilution algorithm and determine the assay range free of hook effect. Assay precision was also established. Following assessment of serial dilutions (1:100 to 1:1,000,000) of the 611 samples analyzed, 70.0% and 85.6% of samples tested with analyzers incorporating 1:100 (Elecsys 2010 and cobas e 411) and 1:400 (Modular Analytics E170) onboard dilution, respectively, fell within the linear range of the assay, providing a final result on the first test. No high-dose hook effect was seen up to the maximum HBsAg serum level tested (870,000 IU/ml) using the dilution algorithm. HBsAg levels were reliably determined across all hepatitis B virus (HBV) genotypes, phases of HBV infection, and stages of disease tested. Precision was high across all analyzers (% coefficient of variation [CV], 1.4 to 9.6; HBsAg concentrations, 0.1 to 37,300 IU/ml). The Elecsys HBsAg II quantitative assay accurately and reliably quantifies HBsAg in routine clinical samples. Onboard dilution minimizes retesting and reduces the potential for error.

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Rosser, S. J., M. J. Alfa, S. Hoban, J. Kennedy, and G. K. Harding. "E Test versus Agar Dilution for Antimicrobial Susceptibility Testing of Viridans Group Streptococci." Journal of Clinical Microbiology 37, no. 1 (1999): 26–30. http://dx.doi.org/10.1128/jcm.37.1.26-30.1999.

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Viridans group streptococci (VGS) are commonly isolated from the blood of hospitalized patients. The E test represents a convenient method for determining the MICs for VGS, but for this purpose it has not been well validated against reference methods. In this study, 180 unselected VGS isolates were identified to a species level, and the MICs of penicillin, cefuroxime, cefotaxime, and vancomycin were determined by both agar dilution and the E test. Available data regarding demographic and laboratory variables for each VGS bacteremic episode were collected, the significance of each VGS isolate was assessed, and the associations between and among laboratory and clinical variables were investigated. Among all VGS isolates, 68.3% (median of three runs) were found to be fully susceptible to penicillin by agar dilution. The E test and agar dilution showed average agreements (within ±1 dilution) of 92.2% for penicillin, 95.7% for cefuroxime 91.3% for cefotaxime, and 86.7% for vancomycin. Agreements over serial E tests and serial agar dilutions were excellent for β-lactam agents (intraclass correlation coefficients, >0.9) but less impressive for vancomycin. Very major error rates for the E test were ≤0.7%, and combined major and minor error rates were within acceptable limits for all antimicrobial agents tested. Lysis-centrifugation culture methods were more often associated with clinically insignificant VGS isolates; otherwise, no associations between clinical and laboratory variables were noted.

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Shaver, Jeremy M., Kenneth A. Christensen, Jerilyn A. Pezzuti, and Michael D. Morris. "Structure of Dihydrogen Phosphate Ion Aggregates by Raman-Monitored Serial Dilution." Applied Spectroscopy 52, no. 2 (February 1998): 259–64. http://dx.doi.org/10.1366/0003702981943329.

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The aggregation of dihydrogen phosphate ion has been studied by Raman spectroscopy during serial dilution of highly concentrated (>5 M) solutions. Factor analysis has been used to recover monomer and aggregate spectra from families of 600–2000 spectra obtained during dilution to about 0.1 M. Spectra of the free aquated dihydrogen phosphate ion and its dimer, trimer, and tetramer have been obtained. There is some evidence for the existence of longer chain aggregates. The serial dilution procedure has been verified by dilution of 2.3 M glycine solution. Only spectra of monomer and dimer ions are recovered. For the well-understood glycine system, the band positions and intensities and the dimerization concentration-dependence are in agreement with previously reported values.

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Kuriyama, Takumi, Nobuyuki Sakai, Mikiya Beppu, Chiaki Sakai, Hirotoshi Imamura, Iwao Kojima, Katsuhiro Masago, and Nobuyuki Katakami. "Optimal dilution of contrast medium for quantitating parenchymal blood volume using a flat-panel detector." Journal of International Medical Research 46, no. 1 (July 31, 2017): 464–74. http://dx.doi.org/10.1177/0300060517715165.

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Objective Similar to perfusion studies after acute ischemic stroke, measuring cerebral blood volume (CBV) via C-arm computed tomography before and after therapeutic interventions may help gauge subsequent revascularization. We tested serial dilutions of intra-arterial injectable contrast medium (CM) to determine the optimal CM concentration for quantifying parenchymal blood volume by flat-panel detector imaging (FD-PBV). Methods CM was diluted via saline power injector, instituting time delays for FD-PBV studies. A red/green/blue (RGB) color scale was employed to quantify/compare FD-PBV and magnetic resonance-derived CBV (MRCBV). Results Contrast values of right and left common carotid arteries did not differ significantly at CM dilutions of ≥20%. RGB analysis of FD-PBV imaging (relative to MR-CVB), showed CM dilution altered the colors (by 16%), increasing red and decreasing blue ratios. Conclusion Diluting CM to 20% resulted in no laterality differential of FD-PBV imaging, with left/right quantitative ratios approaching 1.1 (optimal for clinical use).

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Walling, Leslie, Craig Schulz, and Michael Johnson. "Dispersion Serial Dilution Methods Using the Gradient Diluter Device." ASSAY and Drug Development Technologies 10, no. 6 (December 2012): 507–13. http://dx.doi.org/10.1089/adt.2011.433.

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Blodgett, Robert J. "Upper and Lower Bounds for a Serial Dilution Test." Journal of AOAC INTERNATIONAL 88, no. 4 (July 1, 2005): 1227–30. http://dx.doi.org/10.1093/jaoac/88.4.1227.

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Abstract A Poisson-binomial model estimates the concentration of a target microbe from a serial dilution test. The maximum likelihood procedure gives an equation whose solution equals the estimate of the concentration. This paper gives bounds for the solution to this equation that require only minimal calculations.

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Brands, M., V. Elia, M. Niccoli, and S. Baumgartner. "Blue print: serial dilution and agitation of aqueous solutions." Focus on Alternative and Complementary Therapies 10 (June 14, 2010): 7–8. http://dx.doi.org/10.1111/j.2042-7166.2005.tb00456.x.

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Blodgett, Robert J. "MEASURING IMPROBABILITY OF OUTCOMES FROM A SERIAL DILUTION TEST." Communications in Statistics - Theory and Methods 31, no. 12 (December 31, 2002): 2209–23. http://dx.doi.org/10.1081/sta-120017222.

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Stallard, Nigel, Mike B. Gravenor, and Robert N. Curnow. "Estimating numbers of infectious units from serial dilution assays." Journal of the Royal Statistical Society: Series C (Applied Statistics) 55, no. 1 (January 2006): 15–30. http://dx.doi.org/10.1111/j.1467-9876.2005.00517.x.

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Schoenborn, Liesbeth, Penelope S. Yates, Bronwyn E. Grinton, Philip Hugenholtz, and Peter H. Janssen. "Liquid Serial Dilution Is Inferior to Solid Media for Isolation of Cultures Representative of the Phylum-Level Diversity of Soil Bacteria." Applied and Environmental Microbiology 70, no. 7 (July 2004): 4363–66. http://dx.doi.org/10.1128/aem.70.7.4363-4366.2004.

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ABSTRACT Representatives of only four well-characterized bacterial phyla were isolated from a pasture soil by using liquid serial dilution culture. In contrast, members of Acidobacteria, Verrucomicrobia, and Gemmatimonadetes and of other poorly represented bacterial lineages were isolated in earlier experiments with solidified versions of the same media. We conclude that, contrary to expectation, liquid serial dilution culture is inferior to culturing on solid media for isolating representatives of many bacterial phyla from soil.

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Bizzaro, Nicola, Kimberlee K. Borden, and Karen A. Flessland. "Comparison of ANA endpoint dilution using the PolyTiter? immunofluorescent titration system and conventional serial dilution." Journal of Clinical Laboratory Analysis 16, no. 2 (2002): 91–94. http://dx.doi.org/10.1002/jcla.10024.

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Guan, Shu Xia, Hai Chun Ye, Xiao Xin Wang, and Ying Ying Fan. "Research on Detecting to Bacterial Concentration by Cultivation-Microscopy Method in the Oil Field Sewage." Advanced Materials Research 726-731 (August 2013): 2837–44. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.2837.

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Bacterial concentration is detected by the cultivation-microscopy method and the serial dilution method in the different oil field sewage. The results indicate that the results are the same when the bacterial concentration in the clear water, simulated water and waterflooded sewage were detected by the cultivation- microscopy method and the serial dilution method. The order of magnitude are the same and quotient are different when the bacterial concentration in the polymer- flooded sewage were detected by those. The bacterial concentration by the cultivation-microscopy method detected is more than by the serial dilution method detected when the waterflooded sewage and the polymer-flooded sewage were joined the biocide. They are used to detect the bacterial concentration in the different concentration scop of polymers, the results are the same in the concentration scop of polyacrylamide under 100mg/L, while the results are very different in the concentration scop of polyacrylamide above 200mg/L.

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42

Blodgett, Robert J. "Testing Deviation for a Set of Serial Dilution Most Probable Numbers from a Poisson-Binomial Model." Journal of AOAC INTERNATIONAL 89, no. 1 (January 1, 2006): 166–71. http://dx.doi.org/10.1093/jaoac/89.1.166.

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Abstract A serial dilution experiment estimates the microbial concentration in a broth by inoculating several sets of tubes with various amounts of the broth. The estimation uses the Poisson distribution and the number of tubes in each of these sets that show growth. Several factors, such as interfering microbes, toxins, or disaggregation of adhering microbes, may distort the results of a serial dilution experiment. A mild enough distortion may not raise suspicion with a single outcome. The test introduced here judges whether the entire set of serial dilution outcomes appears unusual. This test forms lists of the possible outcomes. The set of outcomes is declared unusual if any occurrence of an observed outcome is on the first list, or more than one is on the first or second list, etc. A similar test can apply when there are only a finite number of possible outcomes, and each outcome has a calculable probability, and few outcomes have tied probabilities.

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Lai, K. Kay-Yin, Linda Cook, Elizabeth M. Krantz, Lawrence Corey, and Keith R. Jerome. "Calibration Curves for Real-Time PCR." Clinical Chemistry 51, no. 7 (July 1, 2005): 1132–36. http://dx.doi.org/10.1373/clinchem.2004.039909.

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Abstract Background: Despite the increasing use of real-time PCR in the diagnosis and management of viral infections, there are no published studies adequately addressing the optimum number of calibrators, the number of replicates of each calibrator, and the frequency with which calibration needs to be repeated. This study was designed to address these issues. Methods: Cycle threshold data (ABI 7700) was collected from >50 consecutive real-time PCR runs for hepatitis B and Epstein–Barr viruses. Our routine calibration curve made from serial 10-fold dilutions run in duplicate was compared with alternative options, including duplicate 100-fold dilutions, inclusion of a low-copy calibrator, and omission of the duplicate determination. Control data were used to examine the use of an average calibration curve made from multiple runs. Results: Use of duplicate serial 10-fold dilutions led to the least imprecision, duplicate 100-fold dilutions had slightly higher imprecision, and calibration curves obtained with singlet measurements showed the greatest imprecision. For patient data, the duplicate 100-fold dilution calibration curve produced results that best matched those from the routine calibration curve. Use of singlet dilutions or inclusion of a low-copy calibrator produced poorer agreement. Variability in controls was lower with a daily calibration curve than with an average calibration curve. Conclusions: Duplicate 100-fold dilution calibration curves produced equivalent results and the same imprecision as curves with more calibrators, and thus are a valid alternative. Laboratories should carefully evaluate the variability resulting from the use of average calibration curves before adopting this approach.

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Harris, David, Joe Olechno, Sammy Datwani, and Richard Ellson. "Gradient, Contact-Free Volume Transfers Minimize Compound Loss in Dose-Response Experiments." Journal of Biomolecular Screening 15, no. 1 (December 11, 2009): 86–94. http://dx.doi.org/10.1177/1087057109351027.

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More accurate dose-response curves can be constructed by eliminating aqueous serial dilution of compounds. Traditional serial dilutions that use aqueous diluents can result in errors in dose-response values of up to 4 orders of magnitude for a significant percentage of a compound library. When DMSO is used as the diluent, the errors are reduced but not eliminated. The authors use acoustic drop ejection (ADE) to transfer different volumes of model library compounds, directly creating a concentration gradient series in the receiver assay plate. Sample losses and contamination associated with compound handling are therefore avoided or minimized, particularly in the case of less water-soluble compounds. ADE is particularly well suited for assay miniaturization, but gradient volume dispensing is not limited to miniaturized applications.

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da Cunha, Marcio Rodrigues, Mario Ricardo Gongora-Rubio, Izabela Dutra Alvim, and Maria Ines Ré. "Fabrication and Testing of an LTCC Microfluidic Serial Dilution Device." Journal of Microelectronics and Electronic Packaging 6, no. 2 (April 1, 2009): 108–13. http://dx.doi.org/10.4071/1551-4897-6.2.108.

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Usually in chemical and biotechnology laboratories, preparing liquid reagents and samples with distinctive concentrations is a basic process applied to all experiments. Most of the time, this process is done by manual pipetting whose accuracy and repeatability depend on the researcher's expertise. In addition, preparing reagents and samples is a time-consuming process, because of the amount of time needed for pipette regulation, suction, and infusion. Buffer solutions are solutions that resist change in hydronium ion and hydroxide ion concentration (and consequent pH) upon addition of small amounts of acid or base, or upon dilution. Their resistance to changes in pH makes buffer solutions useful for chemical and biochemical processes. A buffer of carbonic acid (H2CO3), bicarbonate (HCO3−), and phosphate (H2PO4−) is present in blood plasma to maintain a pH between 7.35 and 7.45. Industrially, buffer solutions are used in fermentation processes and in setting in vivo conditions for biotechnological experiments, as well as in chemical analysis and calibration of pH meters. The present work reports the potential of 3D LTCC (Low Temperature Cofired Ceramics) to obtain microfluidic structures for the continuous production of buffer solutions with different pH levels. Design, device simulation, and fabrication as well as experimental results are presented.

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Blodgett, Robert J. "Does a serial dilution experiment's model agree with its outcome?" Model Assisted Statistics and Applications 5, no. 3 (August 12, 2010): 209–15. http://dx.doi.org/10.3233/mas-2010-0157.

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Zhang, Yi, Dong Jin Shin, and Tza-Huei Wang. "Serial dilution via surface energy trap-assisted magnetic droplet manipulation." Lab on a Chip 13, no. 24 (2013): 4827. http://dx.doi.org/10.1039/c3lc50915j.

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Libicher, Kai, and Hannes Mutschler. "Probing self-regeneration of essential protein factors required for in vitro translation activity by serial transfer." Chemical Communications 56, no. 98 (2020): 15426–29. http://dx.doi.org/10.1039/d0cc06515c.

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Yan, Yan, Eiko E. Kuramae, Peter G. L. Klinkhamer, and Johannes A. van Veen. "Revisiting the Dilution Procedure Used To Manipulate Microbial Biodiversity in Terrestrial Systems." Applied and Environmental Microbiology 81, no. 13 (April 17, 2015): 4246–52. http://dx.doi.org/10.1128/aem.00958-15.

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ABSTRACTIt is hard to assess experimentally the importance of microbial diversity in soil for the functioning of terrestrial ecosystems. An approach that is often used to make such assessment is the so-called dilution method. This method is based on the assumption that the biodiversity of the microbial community is reduced after dilution of a soil suspension and that the reduced diversity persists after incubation of more or less diluted inocula in soil. However, little is known about how the communities develop in soil after inoculation. In this study, serial dilutions of a soil suspension were made and reinoculated into the original soil previously sterilized by gamma irradiation. We determined the structure of the microbial communities in the suspensions and in the inoculated soils using 454-pyrosequencing of 16S rRNA genes. Upon dilution, several diversity indices showed that, indeed, the diversity of the bacterial communities in the suspensions decreased dramatically, withProteobacteriaas the dominant phylum of bacteria detected in all dilutions. The structure of the microbial community was changed considerably in soil, withProteobacteria,Bacteroidetes, andVerrucomicrobiaas the dominant groups in most diluted samples, indicating the importance of soil-related mechanisms operating in the assembly of the communities. We found unique operational taxonomic units (OTUs) even in the highest dilution in both the suspensions and the incubated soil samples. We conclude that the dilution approach reduces the diversity of microbial communities in soil samples but that it does not allow accurate predictions of the community assemblage during incubation of (diluted) suspensions in soil.

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Gough, Kevin C., Keith Bishop, Robert A. Somerville, Nora Hunter, and Ben C. Maddison. "A sensitive 301V BSE serial PMCA assay." F1000Research 5 (October 18, 2016): 2529. http://dx.doi.org/10.12688/f1000research.9735.1.

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The prion strain 301V, is a mouse passaged form of bovine spongiform encephalopathy (BSE). It has been used as a model of BSE for more than 20 years, in particular in the investigation of tissue distribution of infectivity, the molecular phenotype and transmission properties of BSE, strain typing assays and prion inactivation studies. Most 301V experiments have required murine bioassay as a method for the quantitation of infectivity. To date this model strain has not been studied with the protein misfolding cyclic amplification assay (PMCA) which detects prion-associated PrPSc protein. The detection of BSE PrPSc by PMCA can be more sensitive than mouse bioassay and is carried out in a much shorter time frame of days as opposed to months/years. Here, we describe the development of a new highly sensitive and specific PMCA assay for murine 301V and assess the sensitivity of the assay in direct comparison with murine bioassay of the same material. This in vitro assay detected, in a few days, 301V at a brain dilution of at least 1x10-9, compared to bioassay of the same material in VM mice that could detect down to a 1x10-8 dilution and took >180 days. The 301V PMCA may therefore offer a faster and more sensitive alternative to live animal bioassay when studying the BSE agent in VM mice.

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