A method which assesses transcript expression by conversion of an RNA template into complementary DNA (cDNA) by reverse transcription. The cDNA is used as a template for exponential amplification by the polymerase chain reaction, a technique which produces a large number of copies of one or more specific DNA sequences via multiple rounds of thermal cycling where DNA is melted, annealed to oligonucleotide primers, and extended using a thermostable DNA polymerase.