A CALORIMETRIC METHOD FOR CONTINUOUS RECORDING OF LYMPHOCYTE-PROLIFERATION

We have developed a calorimetric technique as an alternative non-radio active method for measuring mitogen-induced lymphocyte proliferation. Power-time curves can be recorded from as few as 2 X 10(5) cells suspe nded in 4 mi medium. This density is, however, too low for the detecti on of proliferation during a 72 h incubation. Cell numbers exceeding 4 x 10(6) suspended in 4 mi medium cause pronounced crowding and are th erefore too high for use during proliferation studies. We found the op timal initial cell concentration to be 2 X 10(6) cells suspended in 4 mi of medium. In a four-channel bioactivity monitor, up to four separa te incubations can be run in parallel. Furthermore, this method offers the advantage of on-line monitoring of cell proliferation throughout the incubation.