Transcription-mediated amplification

Transcription-mediated amplification is a nucleic acid amplification technique used in molecular biology research, as well as in clinical laboratory settings for the rapid diagnosis of certain infections, usually of bacterial origin. In contrast to similar techniques such as Polymerase chain reaction and Ligase chain reaction, this method involves RNA transcription (via RNA polymerase) and DNA synthesis (via reverse transcriptase) to produce RNA amplicon from a target nucleic acid. This technique can be used to target both RNA and DNA.

TMA has several other differences in comparison to PCR:

- TMA is isothermal; a water bath or heat block is used instead of a thermal cycler.

- TMA produces RNA amplicon rather than DNA amplicon. Since RNA is more labile in a laboratory environment, this reduces the possibility of carry-over contamination.

- TMA produces 100-1000 copies per cycle (PCR and LCR produce only two copies per cycle). This results in a 10 billion fold increase of DNA (or RNA) copies within about 15–30 minutes.

From: http://www.gen-probe.com