Received February 28, 2019
Accepted August 20, 2019

Objective: To report on a device designed for the vitrification of germinative tissue and a step-by-step vitrification/warming protocol. Methods: Six fragments of cortical germinative tissue were obtained from a human ovary. Two fragments were randomly chosen and sent to histological analysis. Four test samples were vitrified, stored for one week in liquid nitrogen (LN), and warmed one week later. The vitrified/warmed fragments were sent to the pathology laboratory where they were morphologically analyzed under an optical microscope (10-40X). Nuclear and cytoplasmic characteristics of the follicular cells, luteal layer, and stroma were analyzed. All existing primordial and primary follicles in the fresh and vitrified/warmed fragments were counted and compared with Mann-Whitney test (p<0.05). Results: Ovarian follicles in different phases of maturation were observed in both fresh and vitrified/warmed fragments, with a predominance of healthy-looking primordial and primary follicles. In the test fragments, the fusocelular architecture supporting the stromal cells exhibited some foci of edema, and were associated with cells with hydropic degeneration, with cytoplasmic fragmentation and eosinophilia. However, there were no signs of tissue necrosis or autolysis. There was no statistically significant difference between the number of follicles found in the control and test tissue fragments (p>0.05). Conclusions: No significant morphological changes were observed between fresh and vitrified/warmed germinative tissue. The vitrification device and protocol tested were shown to be effective in the preservation of human follicles, and should be considered for the banking germinative tissue for the restoration of fertility of women who are submitted to life-saving sterilizing treatments.