Mutant polymerases and uses thereof

A method of amplifying a target nucleic acid in a reverse transcriptase polymerase chain reaction (RT-PCR) comprising:

• (i) forming an assay mixture comprising
• (A) a sample comprising the target nucleic acid, wherein the target nucleic acid is a target RNA,
• (B) a primer which anneals to the target RNA and its DNA equivalent and a primer which anneals to cDNA transcribed from the target RNA,
• (C) a buffer, and
• (D) at least one mutant polymerase comprising a polypeptide sequence having
• at least 95% sequence identity to SEQ ID NO:
• 1 or SEQ ID NO:
• 2,
• reverse transcriptase activity and DNA polymerase activity, and
• a D732N substitution according to the numbering of wild type Taq polymerase of SEQ ID NO:
• 1, wherein the assay mixture does not include a separate reverse transcriptase enzyme in an amount sufficient to generate cDNA from the target RNA or in an amount sufficient to initiate reverse transcription of the target RNA;
• and
• (ii) amplifying the target nucleic acid in the assay mixture in RT-PCR, wherein the amplifying does not include a separate reverse transcriptase enzyme in an amount sufficient to generate cDNA from the target RNA or in an amount sufficient to initiate reverse transcription of the target RNA.