Figure 3.

Ability of the CD34⁺ to generate MKs subsequent to thawing. (A) Number of MKs obtained from CD34⁺ cells previously frozen with 1M trehalose or according to the classical method, following short (20 days) and long (3 months) durations of cryopreservation. The evaluation was performed by trypan blue dye exclusion assay on the day of thawing (day 0), and after 6 and 12 days of MK differentiation. Data are expressed as the mean ± standard deviation of three separate experiments. (B and C) Percentage of CD61⁺ at different stages of MK differentiation. MKs were obtained from (B) fresh CD34⁺ or (C) after thawing. Cells were previously cryopreserved with 1M trehalose or 10% Me₂SO + 90% FBS at short and long durations of cryopreservation. The evaluation was performed by flow cytometry of typical anti-CD61⁺ PE antibody on the day of thawing (day 0), and after 6 and 12 days of MK differentiation. Data are expressed as the mean ± standard deviation of four separate experiments. MK, megakaryocyte; FBS, fetal bovine serum.