A simplified [3H] serotonin release assay for the detection of platelet antibodies

The [3H] platelet serotonin release assay is a sensitive means for detecting antiplatelet antibodies. We have found that by using prelabeled frozen platelets which have been treated with the cryoprotective agent dimethyl sulfoxide (DMSO) the performance of this assay can be facilitated without interfering with its sensitivity. There was 100% correlation between the standard [3H] platelet serotonin release assay using fresh platelets and the modified assay using prelabeled, frozen, cryopreserved platelets when sera from 12 patients with known antiplatelet antibodies were tested. When normal serum samples (n = 111) were tested against ten platelet donors, a false-positive rate of 3.9% was observed. This modification provides a simple means for quickly screening large numbers of potential platelet donors at one time.