Question: What is reverse transcription, and how should I code for the procedure? Washington Subscriber Answer: Transcription is a procedure that involves synthesizing RNA from a DNA template. Reverse transcription is just the opposite process. It involves using a DNA polymerase enzyme called reverse transcriptase to transcribe a single-stranded RNA sequence into a double-stranded DNA sequence. If your lab performs reverse transcription as part of a molecular diagnostics study, you should report the service as 83902 (Molecular diagnostics; reverse transcription).