H-D-Phe-Pip-Arg-pNA (S-2238) dihydrochloride, a chromogenic substrate, is patterned after the N-terminal portion of the A alpha chain of fibrinogen, which is the natural substrate of thrombin. H-D-Phe-Pip-Arg-pNA dihydrochloride is specific for thrombin and is used to measure antithrombin-heparin cofactor (AT-III). The AT-III assay using H-D-Phe-Pip-Arg-pNA dihydrochloride is sensitive, accurate, and easy to perform.

S961 TFA is A high affinity insulin receptor (IR) antagonist with IC50 for hir-a, hir-b and human insulin-like growth factor I receptor (higf-ir) at 0.048, 0.027 and 630 nM, respectively.

Tau protein (592-597), Human (TFA) is a peptide fragment of human Tau protein.