A DNA polymerase which catalyzes the polymerization of DNA, using DNA, RNA DNA:RNA hybrids templates. Besides possessing 5’-3’ DNA polymerase activity, the enzyme also possess some RNase H activity, which degrades RNA:DNA hybrids. It is used primarily for the synthesis of first second strand cDNA primer extensions. To a lesser extent, it is used for RNA sequencing the preparation of probes for hybridization.