Abstract: The present invention relates to an improved method for collecting blood. The present invention also relates to a method of collecting blood whereby tissue plasminogen, tissue plasminogen activator inhibitor and other serine proteases, serine protease inhibitors and components that are produced or destroyed through the action of serine proteases in collected blood are stabilized. In addition, the present invention provides a method for collecting blood that reduces the hemolysis (lysis of red blood cells). Using the blood collecting method of the present invention, reliable control plasmas can be manufactured.

Abstract: The present invention relates to an improved method for measuring soluble fibrin utilizing a genetically modified tissue plasminogen activator protein as a substrate.

Abstract: An affinity gel for the isolation of serine proteases from a biological sample. The affinity gel is modified for specificity for serine proteases by coupling an organophosphorous compound to the gel. The reaction is carried out in two steps. The hydrophilic gel is reacted with a phosphoryl trifluoride and then the coupled gel is further reacted with an alcohol to form the organophosphorous compound.

Abstract: The invention relates to a fully solubilizable fibrin based composition, which is characterized by the combination that the fibrin is desAA-fibrin or desAA-fibrin from which the C-terminal portions of the .alpha.-chains have been removed by enzymatic digestion, and that the solubilizing agent is a tetrapeptide containing the amino acid sequence -L-prolyl-L-arginyl-, preferably glycyl-L-prolyl-L-arginyl-L-prolin.The full solubility of the fibrin makes possible new uses within the area of determination of important fibrinolytical parameters, and the invention also relates to three such important alternative uses. A first use according to the invention is the use of the composition in connection with detection or quantification of the activity of the enzyme tissue plasminogen activator.