The presence of particulate matter is a result of fibrinogen converting to insoluble fibrin resulting from freezing and thawing human platelet lysate. This particulate matter does not indicate contamination of any sort, and does not have any negative impact on cell culture performance. To avoid particulate matter from forming, we suggest minimal freeze / thaw cycles when using our products.
Should insoluble particles appear in thawed hPL we recommend removing particles by centrifuging at 3,400 x g for 3-5 minutes.
If clotting or insoluble particles appears in the final medium, we recommended filtering the complete culture medium after diluting in the basal medium to remove insoluble particles. Filtering the completed medium (e.g. 5%), after hPL is diluted in the basal medium, will not affect supplemented cell culture performance. However, filtering is NOT recommended for 100% concentrate hPL as this may reduce cell culture performance.