Using the Quantitative Competitive RT-PCR Technique to Analyze Minute Amounts of Different mRNAs in Small Tissue Samples

The reverse-transcriptase-polymerase chain reaction (RT-PCR) can be used to determine minute amounts of mRNAs in tissue samples by co-amplification of a quantified amount of a competitive sequence (internal standard), so-called quantitative competitive (qc) RT-PCR. The first description of qcRT-PCR was provided by Wang et al. (1 ). As an internal standard, an RNA template with the same primer sites as the target mRNA was reverse-transcribed. The amplified PCR products differed in size and were separated by agarose gel electrophoresis. The presence of ³² P-labeled 5′ primer allowed quantification by scintillation counting.