FIGURE 3.

Comparison of cell viability of human PBMC cryopreserved with different devices. PBMC from healthy volunteers (n = 6, color-coded) were isolated and frozen using the indicated methods. Cell viability before freezing was measured for the baseline. Cells frozen in a controlled rate freezer were moved to a liquid nitrogen dewar upon completion of freezing cycle, whereas cells frozen in CoolCell and Mr. Frosty were transferred from −80°C to liquid nitrogen the following day. Ten days after transfer to liquid nitrogen, cells were thawed and viability measured. Results represent observations in at least 2 independent experiments.