Collecting blood platelets. Bags receiving a flow of platelets (thrombocytes, yellow) that have been separated out from donor blood. The platelets are essential for blood clotting, and are suspended in plasma, the liquid component of blood. The plasma and platelets could have been obtained by pressure separation of centrifuged blood. The platelets may also have been concentrated from an initial plasma sample. Another method is the direct filtration of blood to remove everything except the plasma and the smallest components, the platelets. Plasma is further processed for a variety of blood products. Platelets are used to treat platelet deficiencies and disorders like thrombocytopenia.