Academic literature on the topic 'Sequenced-Defined polymers'

Abstract The polymerase chain reaction (PCR) (Bell, 1989) has proven a valuable tool for amplifying defined DNA sequences, even if they are available in only minute amounts, to obtain quantities that can be analyzed and/or sequenced. Using a variety of thermostable DNA polymerase enzymes (e.g., Tag), the PCR can quickly and efficiently amplify a genetic sequence utilizing an automated thermocycler (Bell, 1989). Thus genes or virus sequences (Chehab et al., 1989; Krone et al., 1990; Meltzer et al., 1990; Saito et al., 1989) present only in a small sample of cells, or in a small fraction of cells in a heterogeneous population can be traced. A specific area of study especially important for PCR has been in the area of human immunodeficiency virus type I/acquired immune deficiency (HIV-1/AIDS) research, as the actual percentage of HIV-I-infected cells in the peripheral blood has been subject of controversy (Ho et al., 1989; Harper et al., 1986).

Abstract Since we first reported our findings regarding in situ amplification of the HIV-1 gag gene in an HIV-1-infected cell line in March 1990 (1), there has been an explosion of research in the area of in situ polymerase chain reaction (in situ PCR). There are over 300 publications describing various forms of in situ gene amplifications (reviewed in 2,3,13) , identifying various infectious agents, tumour marker genes, cytokines, growth factors and their receptors, and other genetic elements of interest, in peer-reviewed journals (1–25). The solution-based PCR method for amplifying defined gene sequences has proved a valuable tool not only for basic researchers but also for clinical scientists. Using even a minute amount of DNA or RNA and choosing a thermostable enzyme from a large variety of sources, the gene of interest can be amplified and then analysed and/or sequenced. Thus genes or segments of gene sequences present only in a small sample of cells or a small fraction of mixed cellular populations can be examined. However, one of the major drawbacks of solution-based PCR is that it does not allow the association of amplified signals of a specific gene segment with the histological cell type(s) (13,14). For example, it would be advantageous to determine what types of cells in the peripheral blood carry aberrant genes in a leukaemia patient and what percentage of leukaemia cells is present after various forms of anti tumour therapy.