Moloney Murine Leukemia Virus Reverse Transcriptase (M-MLV RT) is an RNA-dependent DNA polymerase that can be used in cDNA synthesis with long messenger RNA templates (>5 kb). The enzyme is a product of the pol gene of M-MLV and consists of a single subunit with a molecular weight of 71 kDa. The RNase H activity of M-MLV RT is weaker than that of the commonly used Avian Myeloblastosis Virus (AMV) reverse transcriptase.