In cases of azoospermia, collection of testicular tissue biopsy is performed, on the one hand to confirm the presence or sperm or the chance of malignancy, and on the other to collect sperm, if any is detected.

Before the biopsy, the levels of FSH, LH and testosterone are measured, to assess the function of the testicles and the seminiferous tubules. If these are found to be high, the chance of testicular dysfunction or absence of sperm is high.

The testicular tissue is collected surgically and treated at an andrology lab, so that sperm suitable for fertilization or future storage is isolated.

Special treatment of the sperm then follows, so that it can be cryopreserved in special tanks, which are placed in liquid nitrogen at -196°C and remain there until used for micro-insemination (ICSI).