Random primers are oligodeoxyribonucleotides (mostly hexamers) used to prepare labeled DNA probes from templates needles for filter hybridization or in situ hybridization and for priming mRNA with or without poly(A) for cDNA synthesis. These primers are truly random primers suitable for DNA synthesis using Klenow fragments containing DNA templates, or for cDNA synthesis using reverse transcriptase containing mRNA templates. To avoid storage buffer interference, random primers are supplied in low-salt buffer.

Performance and quality testing:
Use control DNA in random primer labeling reactions to confirm incorporation of radiolabeled nucleotides.