Reverse Psychology

Reverse Transcriptases Commonly Used for RT-PCR

Reverse transcriptase-PCR (RT-PCR)--a method for assessing gene expression, detecting low copy number mRNA transcripts, and generating complementary DNAs (cDNAs) for cloning--converts an RNA template to its DNA counterpart with a reverse transcriptase enzyme. The cDNA is then amplified by PCR. Although the technique appears relatively painless, researchers using RT-PCR may encounter several pitfalls. For instance, reverse transcribing long mRNA templates or those with a high degree of secondary structure may be difficult with standard reverse transcriptases. The technique itself can be time consuming, because RNA extraction and purification is typically required before the reactions can take place. In addition, researchers who wish to use RT-PCR to quantitate steady-state levels of mRNA face challenges.

Fortunately, a number of companies have introduced products that overcome or mitigate many of the problems associated with RT-PCR. This article will review new developments in reverse transcriptases, kits for direct...