FAQ: What are the main causes of reaction failure using T7 RNA Polymerase?

T7 RNA Polymerase is extremely sensitive to salt inhibition. Monovalent salt concentration should not exceed 20mM. DNA template should be prepared free of salt.

RNase contamination degraded the RNA product. We recommend using RNase inhibitor (NEB #0314 or #M0307) in reaction at 1 unit/ul. Use ultra-pure water and make sure the DNA template has been phenol/chloroform extracted.