A rapid, topographical platelet activation assay.

Platelets are central in maintaining normal haemostasis and are responsible for the cessation of blood loss following vascular injury. Platelet adhesion, leading to thrombus formation, involves rapid and distinct morphological changes culminating in cell aggregation. Rapid and highly specific platelet diagnostic tests are currently being developed to enable monitoring of drug response in patients with cardiovascular diseases. For a diagnostic device to be effective it needs to be rapid and simple, requiring minimal user interaction and providing results with minimal delay. This study describes the development of a rapid, label free platform for assay platelet function and demonstrates its use to monitor the influence of anti-thrombotic drugs. A rapid, single-step cell purification surface immobilises platelets from whole blood onto a protein array at specific locations used to define the assay site. Morphological changes and cell aggregation properties of activated platelets are exploited and combined within a label free, rapid, dye displacement chamber to determine cell morphology. Stimulation-dependent changes in cell morphology are described using both high resolution AFM imaging and a dye displacement platform.