The use of reverse transcriptase to synthesize cDNA
Reverse Transcriptase is an enzyme that can be used to bond DNA nucleotides to an RNA template (reverse of transcription). This enzyme is produced by retroviruses such as HIV. There are usually multiple copies of mRNA in a cell. Being able to extract them and use them as templates to make DNA is easier than trying to extract and use DNA to make DNA. Reverse transcriptase allows the mRNA to be used to synthesize DNA. DNA produced in this way is called cDNA or complimentary DNA. This DNA lacks introns which makes it easier to insert into prokaryotic cells.