Thrombin from human plasma,lyophilized powder, =1,000 NIH units/mg protein (E1%/280, 18.3)

Synonym: Factor IIa

CAS Number: 9002-04-4

EC Number: 232-648-7

Enzyme Commission (EC) Number: 3.4.21.5

MDL number: MFCD00082072

Analysis Note
The NIH assay procedure uses 0.2 ml diluted plasma (1:1 with saline) as a substrate and 0.1ml of thrombin sample (stabilized in a 1% buffered albumin solution) based on a modification of the method of Biggs. Only clotting times in the range of 15-25 seconds are used for determining thrombin concentrations.

Biochem/physiol Actions
Serine protease that selectively cleaves Arg-Gly bonds in fibrinogen to form fibrin and fibrinopeptides A and B.

Unit Definition
Activity is expressed in NIH units obtained by direct comparison to a NIH Thrombin Reference Standard.

Physical form
Lyophilized from saline sodium citrate buffer, pH 6.5.