RT–PCR is a variation of PCR, or polymerase chain reaction. The two techniques use the same process except that RT–PCR has an added step of reverse transcription of RNA to DNA, or RT, to allow for amplification. ... Since the COVID-19 virus only contains RNA, real time or conventional RT–PCR is used to detect it.///// Quote from Google. I understood that for COVID case it is only RT PCR being used.