Complementary DNA is made from a single-stranded RNA template in a procedure catalyzed by the enzyme reverse transcriptase.
In prokaryotes, cDNA is frequently used to clone eukaryotic genes.
Messenger ribonucleic acid (mRNA) is a single-stranded RNA molecule that corresponds to a gene's genetic sequence and is read by a ribosome during the protein synthesis process.
Reverse transcriptase, a DNA polymerase that may use either DNA or RNA as a template, produces complementary DNA (cDNA), which is a DNA copy of a messenger RNA (mRNA) molecule.