Single-step elimination of contaminating DNA prior to reverse transcriptase PCR.

The reverse transcriptase-polymerase chain reaction (RT-PCR) provides an effective m e t h o d for detecting very small a m o u n t s of a specific mRNA in a small sample of total RNA.O,2) Unfortunately, for purposes of detecting RNA by this procedure, after the initial step of converting RNA i n t o cDNA using reverse transcriptase, the multiple rounds of amplification catalyzed by DNA polymerase are equally effective at a m p l i f y i n g either the cDNA or cont a m i n a t i n g g e n o m i c DNA. Even minuscule a m o u n t s of c o n t a m i n a t i n g DNA (<1%) can produce a falsepositive amplification signal in an RT-