Three micrograms of total RNA is primed with random primer oligonucleotides and reverse-transcribed by MMLV reverse transcriptase in 20 µl final volume. The RT reaction is stopped by heating at 65°C for 10 minutes. The cDNA is delivered in 1x RT buffer. (1x RT Buffer: 50 mM Tris-HCl, pH 8.3, 75 mM KCl, 3 mM MgCl2, 10 mM DTT). 1 µl cDNA is sufficient for one PCR reaction. The 5' end of human beta-actin cDNA has been amplified by PCR from all cDNAs.