Definitions for "Polymerase chain reaction"
A molecular technique in which the DNA of plant or microbe is used to generate banding patterns that can be used in determining the relationship between organisms.
(PCR TM, performed pursuant to an agreement with Roche Molecular Systems, Inc.) is a highly efficient method to amplify low levels of specific DNA sequences in a sample to reach the threshold of detection. Two short DNA "primers", oligonucleotides (small portions of a single DNA strand) specific for the pathogenic DNA sought whose sequence flanks that section of DNA to be amplified, are used. Repeated cycles of DNA denaturation (separation of the double DNA strands), primer annealing (recombination of the double-stranded structure) and extension of the primed DNA sequence (by the enzyme DNA polymerase in the presence of added purine and pyrimidine bases) are performed. Each cycle doubles the amount of specific DNA sequence present and results in an exponential accumulation of the DNA fragment being amplified. The reaction products are hybridized to a radioactively labeled DNA segment complementary to a short sequence of the amplified DNA. Following electrophoresis, the radiolabeled product of specific size is detected by autoradiography.
Molecular technique used to replicate and amplify a fragment of DNA
Keywords:  bcr, sensitive, marrow, test, hiv
A very sensitive test used to detect very low levels of bcr-abl in marrow stem cells.
A very sensitive test for the presence of HIV.