The assay time is considerably reduced from about an hour to few minutes by the newly reported RTF-EXPAR method which uses reverse transcriptase-free (RTF) approach for conversion of RNA in DNA followed by EXPAR (Exponential Amplification Reaction) for amplification at single temperature.
Controlling the rate of COVID-19 spread requires an accurate and a faster virus testing strategy. RT-PCR (reverse transcriptase polymerase chain reaction), the most accurate testing method being currently employed is a two-step test that takes around 60 minutes per sample.
Die Forscher der University of Birmingham haben über eine neuartige Methode zum Nachweis von SARS-CoV-2 berichtet. Dies könnte ein viel schnelleres Testen ermöglichen und ist ausreichend empfindlich.
Der virale RNA-Nachweis von RT-PCR (Reverse Transkriptase-Polymerase-Kettenreaktion) beinhaltet die Umwandlung von viraler RNA in komplementäre DNA (cDNA), gefolgt von der Amplifikation der cDNA durch eine quantitative PCR (qPCR). Die cDNA wird dann mit einem Fluoreszenzfarbstoff nachgewiesen. Dies dauert bis zu einer Stunde.
The assay time is considerably reduced from about an hour to few minutes by the newly reported RTF-EXPAR method which uses reverse transcriptase-free (RTF) approach for conversion of RNA into DNA followed by EXPAR (Exponential Amplification Reaction) for amplification at single temperature. The amplification taking place at a single temperature is the key to speed, because it avoids lengthy heating and cooling steps of RT-PCR. Further, the section of DNA being amplified is smaller compared RT-PCR. Hence, EXPAR generates up to 108 strands of DNA product in few minutes. The duplex formation is monitored, as in RT-PCR method using fluorescent dye, SYBR Green.
Interessanterweise kann die neue Methode modifiziert werden, um mehrere andere Infektionskrankheiten nachzuweisen, die durch RNA-Viren verursacht werden, zum Beispiel Ebola, RSV usw.
Quelle (n):
Carter et al. (2020). Sub-5-Minuten-Nachweis von SARS-CoV-2-RNA mit einer Reverse Transcriptase-Free Exponential Amplification Reaction, RTF-EXPAR. Vordruck. Veröffentlicht bei medRxiv Gepostet am 04. Januar 2021. DOI: https://doi.org/10.1101/2020.12.31.20248236
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