Recovery of nucleated cord blood cells after storage in liquid nitrogen was evaluated. Red cells were depleted using Ficoll-Paque? or Puregene® red cell lyses. Freeze Medium contained 10% dimethylsulfoxide and 20% serum for cryoprotection. Recovery of the original cell population remaining serviceable for fluorescence activated cell sorting (FACS) was 12 ± 10% (average ± standard deviation), with a range of 1% to 55%. Viability measured by FACS analysis after freezing was significantly lower than that of the same specimens prior to freezing, 62 ± 20% compared to 91 ± 11% (p < 0.001). Percentage CD45+34+ cells were the same for fresh and frozen cells. Gestational age at which specimens were collected had no effect on the percent cells carrying the CD45+34+ markers. We conclude that better cryoprotective supplements are needed to insure consistent high recovery of viable nucleated umbilical cord blood cells after preservation in liquid nitrogen.
Print ISSN: 1619-3997
Volume: 32, 09/2004
Pages: 430 - 433