The lumi-aggregometer: a new instrument for simultaneous measurement of secretion and aggregation by platelets.

We have developed a new instrument that simultaneously monitors aggregation and secretion of ATP from the same sample of platelets. Aggregation is determined by the usual turbidimetric method; secretion of ATP is followed by measuring luminescence from the firefly luciferase system at right angles to the aggregometer light path. Data are recorded on a two-pen strip chart recorder and reveal the temporal relations between the two platelet responses.