This high-purity Ambion® enzyme is a mix of cloned RNA polymerase and RNase inhibitor. It has a high specificity for its promoter, transcribing large amounts of RNA with no cross talk between promoters. It is supplied in one tube containing 30,000 U at a concentration of 200 U/ µL. The enzyme incorporates radiolabeled nucleotides along with many modified nucleotides. Inclusion of RNase inhibitor provides broad-spectrum protection against enzymatic degradation of the synthesized RNA, making the enzyme ideal for the synthesis of RNA for blot and in situ hybridization probes, RPA analysis, in vitro translation, and antisense RNA.
Unit Definition: One unit catalyzes the incorporation of 1 nmole of NTP into acid-insoluble material in 60 min using a linearized template approximately 300 nt in length. Using a short linear template in the unit assay is essential because it allows the measurement of the rate limiting initiation step. Units determined from long (3,000 nt) supercoiled templates appear to be 3- to 5-fold higher, but they measure the elongation rate that is much faster than the initiation rate. Thus, one unit defined with a linearized 300 nt template actually contains more polymerase activity than a unit defined using a 3,000 nt supercoiled template.
For Research Use Only. Not for use in diagnostic procedures.