Abstract: A method is provided for determining in real time the course of proteolytic, e.g., thrombin activity, in a sample of clotting blood or plasma. By frequent mixing of a sample, clot formation may be controlled in a dense manner such that the majority of the sample remains fluid. This will inhibit cell precipitation and allow for informative monitoring as signal substrate is added.

Abstract: A reliable, fast and convenient method is provided to determine the change in concentration of enzyme in time in a biological medium in the presence of a signal substrate that corrects for substrate consumption, color-dependency of the signal and non-linearity between the concentration of the leaving group of the signal substrate and the amount of signal. The method comprises the measurement of a calibrator curve in a suitable medium, such as a buffer, to determine the characteristics of the measured curve. These characteristics will then allow to obtain this whole curve or a sufficient part thereof again through a mathematical procedure based on a single-point measurement in a sample of a medium in which the enzyme generation takes place. This has the great advantage that there is no need to measure the whole calibrator curve in each individual medium, since a single-point measurement is adequate.

Abstract: Methods and kits to determine thrombin activity are provided. They have the great advantage that there is no need to measure the whole calibrator curve in each individual medium, since a single-point measurement is adequate.

Abstract: A reliable, fast and convenient method is provided to determine the change in concentration of enzyme in time in a biological medium in the presence of a signal substrate that corrects for substrate consumption, color-dependency of the signal and non-linearity between the concentration of the leaving group of the signal substrate and the amount of signal. The method comprises the measurement of a calibrator curve in a suitable medium, such as a buffer, to determine the characteristics of the measured curve. These characteristics will then allow to obtain this whole curve or a sufficient part thereof again through a mathematical procedure based on a single-point measurement in a sample of a medium in which the enzyme generation takes place. This has the great advantage that there is no need to measure the whole calibrator curve in each individual medium, since a single-point measurement is adequate.

Abstract: A method is provided for determining in real time the course of thrombin activity in a sample of clotting blood or plasma as it appears in and disappears from the sample which comprises adding a signal substrate to said sample, said signal substrate causing a detectable signal related to the amount of conversion product formed upon reaction by the generated proteolytic activity, monitoring the signal development in time in said sample to provide a curve, and mixing said sample frequently so that clot formation occurs in a dense manner such that the majority of the sample remains fluid and that cell precipitation is inhibited, wherein said monitoring and mixing steps are repeated and performed in an alternate way.