Method for determining thrombocyte function in a whole blood sample, wherein the method comprises the following steps: a) using a measuring cell, wherein the measuring cell comprises the following elements: i) a retention chamber for retaining the sample, ii) a capillary through which the sample is conducted from the retention chamber into a measuring chamber, iii) a measuring chamber which is divided by a partition element into two compartments, wherein the first compartment accommodates the sample from the capillary, iv) a partition element which divides the measuring chamber into two compartments and which has an aperture through which the sample can flow from the first compartment into the second compartment; b) filling the retention chamber of the measuring cell with the sample; c) placing the measuring cell in a device for automatic determination of thrombocyte function, wherein the device comprises the following elements: i) means for applying negative pressure in the measuring chamber of the measuring cell, ii) means for determining the flow rate of the sample, which is generated when negative pressure is applied in the measuring chamber of the measuring cell; d) applying negative pressure in the measuring chamber of the measuring cell and conducting the sample through the capillary and through the aperture in the partition element; e) determining the flow rate of the sample, which is drawn through the capillary and through the aperture in the partition element as a result of the application of negative pressure; f) determining an initial flow rate IF; g) determining the closure time CT, the end point of the closure time being the time at which the flow rate was less than 10% of the initial flow rate IF for a period of three seconds; characterized in that the thrombocyte function is determined according to the following formula: PHC = 100 - FF % of IF CT - CT M + 90 where FF = final flow rate, IF = initial flow rate, CT = closure time of the sample [s], CT M = reference closure time [s] for normal thrombocyte function, and where - if, over a test period of at least 300 seconds, it was not possible to measure a final flow rate reduced by 90% with respect to the initial flow rate and it is thereby not possible to determine a closure time - 300 seconds are assigned to the closure time CT and the actual flow rate at this time is determined as the final flow rate. a) using a measuring cell, wherein the measuring cell comprises the following elements: i) a retention chamber for retaining the sample, ii) a capillary through which the sample is conducted from the retention chamber into a measuring chamber, iii) a measuring chamber which is divided by a partition element into two compartments, wherein the first compartment accommodates the sample from the capillary, iv) a partition element which divides the measuring chamber into two compartments and which has an aperture through which the sample can flow from the first compartment into the second compartment; i) a retention chamber for retaining the sample, ii) a capillary through which the sample is conducted from the retention chamber into a measuring chamber, iii) a measuring chamber which is divided by a partition element into two compartments, wherein the first compartment accommodates the sample from the capillary, iv) a partition element which divides the measuring chamber into two compartments and which has an aperture through which the sample can flow from the first compartment into the second compartment; b) filling the retention chamber of the measuring cell with the sample; c) placing the measuring cell in a device for automatic determination of thrombocyte function, wherein the device comprises the following elements: i) means for applying negative pressure in the measuring chamber of the measuring cell, ii) means for determining the flow rate of the sample, which is generated when negative pressure is applied in the measuring chamber of the measuring cell; i) means for applying negative pressure in the measuring chamber of the measuring cell, ii) means for determining the flow rate of the sample, which is generated when negative pressure is applied in the measuring chamber of the measuring cell; d) applying negative pressure in the measuring chamber of the measuring cell and conducting the sample through the capillary and through the aperture in the partition element; e) determining the flow rate of the sample, which is drawn through the capillary and through the aperture in the partition element as a result of the application of negative pressure; f) determining an initial flow rate IF; g) determining the closure time CT, the end point of the closure time being the time at which the flow rate was less than 10% of the initial flow rate IF for a period of three seconds; characterized in that the thrombocyte function is determined according to the following formula: PHC = 100 - FF % of IF CT - CT M + 90 where FF = final flow rate, IF = initial flow rate, CT = closure time of the sample [s], CT M = reference closure time [s] for normal thrombocyte function, and where - if, over a test period of at least 300 seconds, it was not possible to measure a final flow rate reduced by 90% with respect to the initial flow rate and it is thereby not possible to determine a closure time - 300 seconds are assigned to the closure time CT and the actual flow rate at this time is determined as the final flow rate.