Figure 1.

Percentage of cell viability measured after thawing of the CD34⁺ cells previously frozen with different concentrations of trehalose or according to the classical method. CD34⁺ cells were frozen with: 0.3, 0.6, 1 and 1.25M trehalose or with 10% Me₂SO + 90% FBS. The viability after thawing was evaluated by Trypan Blue dye exclusion assay. Data were analyzed using Student's t-test and are expressed as the mean ± standard deviation of five separate experiments. *P<0.05. Cell viability (%) = number of recovered cells after thawing ×100/number of non-cryopreserved cells (NT, 100% viability). Me₂SO, dimethyl sulfate; FBS, fetal bovine serum.