Evaluation of methods for preparing pure lymphocyte suspensions from peripheral blood.

one glass bead of 3 mm diameter per 5 mnl of blood. If this is not practicable blood may be collected into heparin and then defibrinated in the same manner after the addition of excess thrombin to neutralize the heparin. Blood from patients on chronic dialysis often requires the addition of thrombin to facilitate defibrination because of the residual heparin and other circulating anticoagulants present after dialysis. Where the suspension is ultimately to be used for tissue typing sterility in these and the following procedures need not be strictly observed, but should the cells be for subsequent culture sterility must be maintained throughout.