[1] By adding a reverse transcriptase enzyme to an RPA reaction, it can detect RNA as well as DNA, without the need for a separate step to produce cDNA.
As with PCR, all forms of RPA reactions can be multiplexed by the addition of further primer/probe pairs, allowing the detection of multiple analytes or an internal control in the same tube.
Like RPA, many of these techniques offer rapid amplification times with the potential for simplified instrumentation, and reported resistance to substances in unpurified samples that are known to inhibit PCR.
[13] In addition, the demands of sample prep (including lysis and extraction of DNA or RNA, if necessary) should be considered as part of the overall time and complexity inherent to the technique.
[14] The general principle of a discrete amplicon bounded by a forward and reverse primer with an (optional) internal fluorogenic probe is similar to PCR.
Although the original 2006 report of RPA describes a functional set of reaction components, the current (proprietary) formulation of the TwistAmp kit is "substantially different" [15] and is available only from the TwistDx supplier.
As with PCR and any other amplification technique, there is obviously a publication bias, with poorly performing primer sets rarely deemed worthy of reporting.