Reverse transcriptase enzymes are RNA-directed DNA polymerases that catalyzes first strand cDNA synthesis from oligonucleotide primed RNA templates.

The majority of reverse transcriptase enzymes are derived from RNA virus genomes and function at temperatures below 42 °C. Empirical's IsoRT is a robust reverse transcriptase that functions effectively at temperatures from 42 to 65 °C and is therefore well-suited to isothermal amplification assays using RNA as a substrate.

IsoRT has been specifically optimized for use with Bst Prime polymerase to carry out RT-LAMP reactions. IsoRT is not recommended for cDNA synthesis or preparation of cDNA libraries used for cloning or sequencing applications.