The mixed lymphocyte response in whole blood: technical aspects.

Experiments were conducted to standardize the response of lymphocytes in whole blood in mixed culture with allogeneic lymphocytes. The following conditions were found suitable: (1) A culture period of 6-8 days. (2) The ratio of stimulator to responder lymphocytes should be 4-8, but may vary from one batch of stimulator cells to another. (3) Tests may be performed in culture tubes with 50-100 microliter blood in a total volume of 2 ml (macrotechnique) or in microplates with 10 microliter of blood in a volume of 0.2 ml (microtechnique). (4) Serum supplement is not required. (5) Results should be expressed as counts/min (cpm) per a given number of responder lymphocytes. Stimulation indices are less reliable.