Method for determining fibrinogen and reagent for determination thereof
AssigneeNippon Shoji Kaisha, Ltd.
InventorMasayasu Enomoto
Life of this patent
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Abstract
A method for determining fibrinogen concentration whereby thrombin or a protease inhibitor having similar activity thereto is added to an undiluted to test sample to convert fibrinogen in the sample to fibrin, and determining a coagulation time fibrinogen is converted in a reaction mixture containing a salt at a high concentration and a reagent therefor. The determination in the presence of a salt at a high concentration permits simplified determination without diluting the test sample.
Claims24
A method for determining a fibrinogen concentration, consisting essentially of adding thrombin or a protease having a similar activity thereto to an undiluted test sample to convert fibrinogen in the sample to fibrin, and determining a coagulation time as a measure of fibrinogen concentration, wherein the conversion of the fibrinogen to fibrin is carried out in a solution containing at least one salt selected from the group consisting of sodium salt, potassium salt and magnesium salt at a concentration, said concentration of the salt being set for a level which provides a coagulation time of 5-100 seconds when the coagulation time is measured at 37.degree. C. using a mixture of a sample containing fibrinogen (275 mg/dl), and a reagent containing thrombin (100 NIHU/ml) and HEPES (100 mM, pH 7-35), at a volume ratio of the sample to the reagent of 1:2.
A reagent for determining a fibrinogen quantity consisting essentially of, a salt selected from the group consisting of sodium salt, potassium salt, and magnesium salt, and 20-500 NIHU/ml thrombin or a protease having a similar activity thereto, wherein the concentration of the salt is set for a level which provides a coagulation time of 5-100 seconds when the coagulation time is measured at 37.degree. C. using a mixture of a sample containing fibrinogen (275 mg/dl), and a reagent containing thrombin (100 NIHU/ml) and HEPES (100 mM, pH 7.35) at a volume ratio of the sample and the reagent of 1:2.
A reagent for determining fibrinogen quantity, consisting essentially of 20-500 NIHU/ml thrombin, 10-400 mM buffer (pH 6.0-9.0), 0.5-4M sodium chloride, and 0.15-1.5M sodium bromide.
A reagent for determining fibrinogen quantity, consisting essentially of 40-200 NIHU/ml thrombin, 30-200 mM buffer (pH 7.0-8.0), 1-3.5M sodium chloride, and 0.3-1M sodium bromide.
Dependencies are inferred from the claim text.