Faster determination of clottable fibrinogen in human plasma: an improved method and kinetic study.

Abstract Clottable fibrinogen in human plasma was determined by measuring spectrophotometrically the increase in turbidity with time due to the fibrinogen-fibrin conversion with thrombin. From the maximal absorbance, Amax, at 450 nm obtained 2 min or less after thrombin as added to plasma, we estimated the fibrinogen concentration in plasma of normal subjects and patients. Analysis of the rate of the absorbance increase yielded the Km value, 1.6 X 10(-5) mol/liter, which closely agrees with the Km of 1.2 X 10(-5) mol/liter obtained by analysis of the fibrinopeptides released from fibrinogen.

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Determination of Plasminogen in Human Plasma by the Lysis Time Method

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655622 ◽

1966 ◽

Vol 16 (01/02) ◽

pp. 001-017 ◽

Cited By ~ 8

Author(s):

W Berg ◽

K Korsan-Bengtsen ◽

J Ygge

Keyword(s):

Human Plasma ◽

Present Method ◽

Blood Donors ◽

Fibrinogen Concentration ◽

Plasmin Activity ◽

Time System ◽

Lysis Time ◽

High Dilutions ◽

Single Determination

SummaryA one-stage lysis time system containing fibrinogen, streptokinase, thrombin, and a known, small amount of plasminogen was used to determine plasminogen in plasma.The known amount of plasminogen was added to the system in order to keep the lysis times relatively short when a highly diluted plasma was tested. High dilutions of plasma were used to reduce the influence of the plasma inhibitors.The calculation of the plasminogen concentration was made on the basis of the correlation: “plasminogen = fibrinogen/lysis time” which was valid in the system. The method allowed determination of plasminogen in plasma with varying fibrinogen concentrations, as the fibrinogen concentration in plasma was considered in the calculation.The presence of “spontaneous” plasmin activity in the plasma did not influence the plasminogen determination. Estimated by this method, the plasminogen content in plasma from 32 blood donors aged 25-45 years was 13.1 ±2.4 casein u/ml. The error of a single determination was 0.3 casein u/ml. The plasminogen content in plasma, determined with the present method, is about 3-4 times higher than the content found when a caseinolytic method is used.

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An improved method for the determination of fluticasone propionate in human plasma

Journal of Pharmaceutical and Biomedical Analysis ◽

10.1016/s0731-7085(99)00213-7 ◽

1999 ◽

Vol 21 (4) ◽

pp. 749-758 ◽

Cited By ~ 15

Author(s):

Lynn Laugher ◽

Terry G Noctor ◽

Andrew Barrow ◽

Janet M Oxford ◽

Trevor Phillips

Keyword(s):

Fluticasone Propionate ◽

Human Plasma ◽

Improved Method

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Optimizing determination of plasma albumin by the bromcresol green dye-binding method.

Clinical Chemistry ◽

10.1093/clinchem/27.1.144 ◽

1981 ◽

Vol 27 (1) ◽

pp. 144-146 ◽

Cited By ~ 6

Author(s):

W S Robertson

Keyword(s):

Reaction Time ◽

Linear Regression ◽

Human Plasma ◽

Protein Composition ◽

Improved Method ◽

Reaction Conditions ◽

Plasma Albumin ◽

Optimal Reaction ◽

Bromcresol Green

Abstract Some modifications of the conditions of the reaction between plasma and bromcresol green have led to an improved method for determination of plasma albumin with the Vickers M300 multichannel analyzer. Dye concentration and reaction time are the factors principally influencing method specificity, but variable protein composition of human plasma also affects it, so that optimal reaction conditions vary from specimen to specimen. Thus a compromise must be reached such that the best conditions for determining plasma albumin over a range of different protein concentrations are achieved. In the proposed method for the Vickers M300 a reaction time of 12 s (the minimum possible) is used. Comparison with "rocket" immunoelectrophoresis gave the following linear regression: y = 10 + 0.79 x (n = 91; r = 0.96).

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