Process and reagent for the determination of the biological activity of heparin in plasma
AssigneeBoehringer Mannheim GmbH
InventorsKnut Bartl, Helmut Lill, Peter Roeschlau, Joachim Ziegenhorn
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Abstract
Method and reagent for the determination of the biological activity of heparin in plasma by adding thrombin or Factor X.sub.a as the proteolytic enzyme and a chromogen substrate of the latter and measuring the dye liberated from the chromogen substrate in the absence of exogenous anti-thrombin III, the improvement consisting of adding, additionally, at least one compound of the formula ##STR1## wherein X is oxygen or the group NR.sub.5 ; and R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are independently selected from hydrogen or alkyl of 1 to 2 carbon atoms.
Claims10
In a method for the determination of the biological activity of heparin in plasma by adding thrombin or factor X.sub.a as a proteolytic enzyme and a chromogen substrate of the latter, and measuring the dye liberated from the chromogen substrate, wherein the determination is carried out in the absence of exogenic anti-thrombin III, the improvement consisting of adding to the reaction mixture 0.02 to 2.0 mole per liter based on the total reaction mixture of at least one compound of the formula ##STR4## wherein X is oxygen or the group NR.sub.5 ;
- and
- R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are independently selected from hydrogen or alkyl of 1 to 2 carbon atoms, so that the proteolytic enzyme acts in the presence of said compound.
Reagent for the determination of the biological activity of heparin in plasma comprising
- 0.01 to 0.2 mol/l of buffer, pH 6 to 9;
- 0.05 to 0.25 mol/l alkali chloride;
- 200 to 1100 NIH/l of thrombin or factor Xa;
- 0.12 to 12 mol/l of chromogen substrate;
- 0 to 0.01 g/l of aprotinin;
- 0 to 0.03 mol/l EDTA;
- 0 to 10 g/l of polyethylene glycol;
- and
- 0.02 to 2.0 mol/l of a compound of the formula ##STR5## wherein X is oxygen or the group NR.sub.5 ;
- and
- R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are independently selected from hydrogen or alkyl of 1 to 2 carbon atoms.
Dependencies are inferred from the claim text.