Transcription of RNA from DNA is the principal step in executing a cell's genetic program. Numerous techniques have been developed to investigate gene expression at the level of transcription, including Northern blot hybridization, RNase protection and reverse transcription coupled with polymerase chain reaction amplification (RT-PCR). RT-PCR is a sensitive and versatile method which can be used to determine the presence of a transcript, to estimate expression levels and to clone cDNA products without the necessity of constructing and screening a cDNA library. Promega's Access RT-PCR System provides a convenient, single-tube, two-enzyme method for generating a cDNA product from an RNA sample.
Promega Notes 58, 43.