RT-PCR (Reverse Transcription PCR)
Definition
A two-stage process: RNA is first reverse-transcribed into complementary DNA (cDNA), then the cDNA is amplified by PCR. Quantitative RT-PCR (RT-qPCR) measures transcript abundance in real time using fluorescent reporters.
- Full name
- Reverse transcription PCR
- Stage 1
- RNA reverse-transcribed into cDNA
- Stage 2
- cDNA amplified by PCR
- Quantitative variant
- RT-qPCR, real-time with fluorescent reporters
Common questions
Why is RNA converted to cDNA before amplification?+
Standard PCR enzymes amplify DNA, not RNA, so reverse transcriptase must first synthesise a complementary DNA copy of the target RNA before the conventional PCR amplification step can proceed.
What does RT-PCR add to forensic body-fluid work that DNA profiling cannot?+
DNA profiling identifies whose cells are present but not which fluid they came from. RT-PCR targets mRNA transcripts expressed differently across tissue types, allowing an examiner to identify the body fluid or tissue source of a stain.
Related terms
- mRNA (Messenger RNA)
- Transcripts encoding proteins, synthesised in the nucleus from DNA templates and translated by ribosomes. mRNA molecules vary greatly in length (hundreds to...
- NanoString nCounter
- A hybridisation and digital counting platform that tallies individual mRNA molecules using fluorescent barcodes, avoiding amplification bias and enabling simultaneous profiling of...
- OSAC Validation
- The framework for forensic assay validation published by the US Organisation of Scientific Area Committees, requiring demonstrations of sensitivity, specificity, mixture performance,...
- RNase
- Ribonuclease enzymes that cleave RNA phosphodiester bonds. Present in blood plasma (RNase A family) and released from cells on death. The activity...
- Tissue-Specific Expression
- The pattern by which certain genes are transcribed at high levels in one tissue and at negligible levels in others, forming the...