Sub-ambient aggregometry: a tool for examining platelet storage at any temperature between 4-22 degrees C.

A specifically modified commercially available aggregometer, referred to as a sub-ambient aggregometer, was used to measure certain parameters of platelet function throughout the temperature range of 4-37 degrees C. Platelet aggregation responses to ADP and stirring (spontaneous aggregation) were found to be maximal at room temperature. The possible relevance of this to routine platelet storage is discussed. Shear-induced light transmission change (SILTC) as a quick, repeatable, non-invasive index of platelet morphology was used to monitor small-sample platelet storage at 4 degrees C and during its subsequent resuscitation at 37 degrees C. This confirmed the combined usefulness of the sub-ambient aggregometer and SILTC measurements for monitoring platelets during storage. Further application of this approach should enable the optimum temperature for the liquid storage of platelets to be defined, which may not necessarily be 22 degrees C as usually employed.