A simple freezing and storage method to preserve the stimulating function of leukocytes in the mixed leukocyte reaction.

Human peripheral blood leukocytes retain their capacity to function as stimulating cells in the one way MLR after freezing and storage at - 70 degrees C by a simple and inexpensive method. This storage method facilitates the use of a standard stimulating pool of cells from three donors which may provide a quantitative assay for testing the ability of cells to respond to allogeneic cells in culture.