Cryopreservation of ovine primordial follicles using dimethyl sulfoxide

Objective: To verify the viability of isolated primordial follicles after exposure to different concentrations of dimethyl sulfoxide (DMSO) and after cryopreservation. Design: Randomized control trial. Setting: Laboratorio Renzo Giuliani, University of Florence, Italy. Animal(s): Thirty- to 40-day-old lambs. Main Outcome Measure(s): Isolated primordial follicles were stained with trypan blue to evaluate the effect of different DMSO concentrations before and after the cryopreservation. Histological structure and follicular mortality were evaluated. Result(s): After the isolation procedure (control), a mean (+/-SE) of 800 +/- 23.86 live primordial follicles/mL were obtained. The number of live follicles in the toxicity test using the DMSO at 0, 0.5, 1.0, 1.5, 2.0, and 2.5 M was 782 +/- 193.96, 754 +/- 172.03, 778 +/- 191.58, 736 +/- 191.92, 476 +/- 122.9, and 316 +/- 83.52, respectively. The number of live follicles at 2.5 M was lower than that in the control procedure. After cryopreservation, the numbers decreased to 0 0 +/- 232 +/- 44.20, 636 +/- 161.82, 628 +/- 181.28, 208 +/- 11.57, and 184 +/- 47.07, respectively at 0, 0.5, 1.0, 1.5, 2.0, and 2.5 M. The number of live follicles at 0, 0.5, 2.0, and 2.5 M were lower than that in the control procedure. Conclusion(s): After cryopreservation, only DMSO concentrations of 1.0 and 1.5 M showed a number of live follicles similar to that of the control procedure. (Fertil Steril((R)) 2003;79(Suppl 1):682-6. 2003 by American Society for Reproductive Medicine.)