An Improved Method for Isolating Alpha Granules and Mitochondria from Human Platelets

We describe a fractionation technique for human platelets which improves upon previous studies (1-3) in that we have obtained greater mitochondrial enrichment than heretofore shown, and provided evidence for heterogeneity of acid hydrolase-associated structures while distinguishing the latter from a rather pure a-granule fraction. We attribute our success to two departures : homogenization by cavitation forces developed by explosive decompression and the elimination of a preliminary centrifugation to remove debris before ultracentrifugation . MATERIALS AND METHODS