Aggregate formation in cryopreserved leukocyte suspensions.

During cryopreservation of leukocytes, a great part of the granulocytes is injured. The latter is responsible for aggregate formation in the suspension and a loss in the number of preserved cells. The formation of aggregates in the suspension is potentiated in the presence of serum in the cryoprotective medium.

A method for preparation of dry thrombin for topical application.

Thrombin for topical hemostasis can be prepared from bovine or human blood plasma. The prothrombin is isolated by means of adsorption on DEAE-Sephadex A-50 and consecutively activated by CaCl2 and thromboplastin. Thrombin is precipitated and purified by acetone.

Antibodies and thermolabile opsonins in the phagocytosis of human red and white blood cells pretreated with formaldehyde.

Erythrophagocytosis is conditioned by serum immunoglobulins. The extent of phagocytosis depends on the haematocrit of the red cell suspension pretreated with formaldehyde. The higher the haematocrit value, the lower will be the extent of phagocytosis.