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NON-RANDOM CELL KILLING IN CRYOPRESERVATION: IMPLICATIONS FOR PERFORMANCE OF THE BATTERY OF LEUKOCYTE TESTS (BLT) - I. TOXIC AND IMMUNOTOXIC EFFECTS
Citation:
Strauss, G. NON-RANDOM CELL KILLING IN CRYOPRESERVATION: IMPLICATIONS FOR PERFORMANCE OF THE BATTERY OF LEUKOCYTE TESTS (BLT) - I. TOXIC AND IMMUNOTOXIC EFFECTS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-90/508 (NTIS PB91199943).
Description:
To eliminate between-tests error in longitudinal studies, for specimen sharing, convenient scheduling, etc., it is necessary to freeze freshly separated leukocytes as well as non-transformed, continuous T lymphocyte (CTL) lines. o test the efficacy of a programmable reezer (temperature falls at an optimal rate), freshly isolated lymphocytes and CTLs were each aliquoted into three sets of vials. wo sets each were frozen in a 1:1 mixture of 15% DMSO in Mixed Medium (MM) and 20% FBS in MM using the standard styrofoam freezer insert for liquid nitrogen refrigerators and a programmed freezer, respectively. he remaining set was held at 20RC during the 2 h freezing process. he cells were thawed and/or washed and assayed for liability and T helper (Th)/Tsuppressor (Ts) ratio. t is clear that inadequate freezing non-randomly damages cells of T cell subpopulations, Th being more sensitive than Ts. urther, it is proved that inadequate cryopreservation can confound results from a number of assessment methods owing to morphological and functional damages. he Battery of Leukocyte Tests (BLT) under development in this laboratory is designed to detect toxic, immunotoxic and genotoxic effects of in vivo mutagens exposure to human blood. t is concluded that minimization of non-random cell losses (as quantitated on the basis of morphology) and preservation of related regulatory cell function is essential if one would assess the in vivo and in vitro states of heterogeneous cells.