Ambion™ RNase H (Ribonuclease H) is isolated from an E. coli strain that over-expresses the gene. RNase H specifically degrades the RNA in RNA:DNA hybrids to produce 3' -hydroxyl and 5' -phosphate terminated products. It is supplied in one tube containing 1,000 U (10 U/ μL). The enzyme will not degrade DNA or unhybridized RNA. RNase H is an integral part of most RNA amplification and NASBA protocols. It can also be used to degrade specific RNAs when the complementary DNA oligo is hybridized, such as poly(A) tail removal from mRNA hybridized to oligo(dT). Ribonuclease H is rigorously tested for contaminating nonspecific endonuclease, exonuclease, RNase, and protease activity.

Unit Definition:
One unit of Ribonuclease H is the amount of enzyme required to increase fluorescence 1.5 RFUs per sec at 37°C using 20 pmol of RNaseAlert™ probe coupled to 1,000 pmol of a complementary oligonucleotide as substrate.