Abstract: The invention relates to methods and kits for stabilising blood cell conjugates in blood samples for subsequent analysis. The invention particularly relates to methods and kits for use in fixing and stabilising platelet aggregates in blood samples, and methods for detecting the degree of platelet aggregation in a sample. The invention extends to kits for monitoring the efficacy of anti-thrombotic treatment regimes using platelet aggregation analysis. Two compositions with aliphatic aldehydes and a buffer are employed in a consecutive order. The second composition comprises addition a chelating agent.

Abstract: The invention provides compositions which stabilise the expression of cell surface markers. The invention further provides methods and kits comprising such compositions for use in stabilising the expression of cell surface markers. The invention is especially concerned with compositions for use in stabilising the expression of cell surface markers (such as cell activation markers) present on blood cells, such as platelets. The invention extends to methods, apparatus and kits for detecting platelet activation, and to kits for monitoring the efficacy of anti-thrombotic treatment regimes.