Theuseofcryopreserved lymphocytes forlongitudinal studies ofimmunefunction andenumeration ofsubpopulations

SUMMARY Theresponses offresh andfrozen lymphocytes tomitogens andantigens havebeencompared using samples collected onfive separate occasions fromonenormal donor. Theday-to-day variation seenwith thefresh cells waseliminated bytheuseoffrozen cells. Thawedcells from onedonor collected ononeoccasion butstudied onfive separate occasions andcompared tofresh cells onthesamedays, showed fluctuations fromdaytodayaswell, confirming that theday-todayvariation seenisduetotechnical andnotbiological phenomena. Cryopreserved cells showed a decrease inresponses tospecific microbial antigens, aslight shift inthePHAdose-response curve, butnosignificant difference inresponses toConAorPWM.Therelative proportion of lymphocyte subpopulations changed with freezing andthawing. Theproportion ofT cells increased slightly andtheproportion ofBcells decreased.