Activity can be mEAsured with the thioredoxin-dependent reduction of insulin using recombinant rat thioredoxin reductase. The test mixture should contain 160 M insulin and 0.2 mM NADPH in 0.1 M potassium phosphate, pH 7.0, containing 2 mM EDTA. In the presence of 5 M human mutant C61S/C72S thioredoxin 1, 7 nM mammalian thioredoxin reductase will give an absorbance decrEAse of approximately 0.10/min at 340 nM. [IMCO Catalog TRX-04]Technical InformationSynonymsTrx1SourceRecombinant mutant human C61S/C72S thioredoxin 1FormulationLyophilized from 50 mM tris-HCl, pH 7.5, 1 mM EDTA