An research on the isolation methods of frozen-thawed human ovarian preantral follicles.

Objective: To explore the effective isolation method for preantral follicles from human frozen-thawed ovarian tissue.

Methods: The ovarian cortical tissue was frozen by direct cover vitrification (DCV). The frozen-thawed ovarian tissue was used for isolation of preantral follicles with collagenase combined with mechanical method and mechanical method alone, respectively.