Lipoprotein enrichment in orange insoluble particulate matter reproducibly appearing in cryoprecipitate

BACKGROUND AND OBJECTIVE: Cryoprecipitate prepared from two whole blood donations from the same donor contained insoluble orange particulate material (OPM). We sought to identify the OPM. MATERIALS AND METHODS: OPM was recovered from the blood product by centrifugation, dissolved in sodium dodecyl sulphate (SDS) and analysed by SDS-polyacrylamide gel electrophoresis and immunoblotting.