Evaluation of human lymphocyte proliferative activity by standard liquid p-scintillation counter and by MicroBeta new generation counter with using solid scintillator
Incorporation of <sup>3</sup>H-thymidine in the lymphocytes of short-term cultures was evaluated by MicroBeta Plus and 1409 DSA β-scintillation counters ("Wallac", Finland). Comparable values of lymphocyte proliferative activity were obtained by both counters in specimens from 16 individuals in response to phytohemagglutinin (PHA) stimulation and in 8 donor-recipient pairs in mixed lymphocyte culture (MLC). MicroBeta Plus counter detected a trend to reduction of proliferative responses to stimulation by PHA and by allogeneic cells in MLC (p < 0.05); an increase of lymphocyte proliferation was detected in cultures without stimulation (p = 0.05). The advantages of the desktop MicroBeta Plus counter are multidetector system, convenient 96-pipe cell harvester and solid scintillator and rapid data processing. This recommends the counter for evaluation of proliferative activity of cultured lymphocytes.