What is cDNA?

cDNA (complementary DNA) is DNA synthesized from a single-stranded RNA (e.g., messenger RNA (mRNA) or microRNA) template in a reaction catalyzed by the enzyme reverse transcriptase. cDNA is often used to clone eukaryotic genes in prokaryotes, as prokaryotes lack the ability to remove introns from pre-mRNA. It's also used in reverse transcription PCR (RT-PCR) to quantify gene expression and in cDNA libraries to study the transcriptome.