AN IMPROVED ASSAY FOR INTERLEUKIN 2 (LYMPHOCYTE GROWTH FACTOR) PRODUCED BY MITOGEN‐ACTIVATED LYMPHOCYTES

Abstract
The continued proliferation of activated T cells requires the presence of a lymphocyte growth factor in the culture medium. This study describes a rapid, highly reproducible assay to quantitatively measure levels of this lymphokine. The use of Concanavalin-A blast cells gives this assay a high degree of flexibility and convenience. It is shown that the lymphokine measured is Interleukin 2. The presence of an inhibitor in the supernatant of mitogen-activated lymphocytes and the species specificity of the factor are demonstrated.