Figure 4.(A)Fine-needle tissue aspiration biopsy of the testis. Local anesthetic is injected around the vas to block testicular sensation.(B)Fine-needle tissue aspiration biopsy of the testis A 21 gauge butterfly needle is inserted into the testis. An assistant applies suction to the needle tubing via a 10mL syringe and the operator makes thrusting movements of the needle into the substance of the testis.(C)Fine-needle tissue aspiration biopsy of the testis while maintaining the suction the needle is removed carefully and any seminiferous tubules protruding from the needle are grasped with fine forceps to avoid them falling back into the puncture hole. With this technique seminiferous tubule sections are sucked into the needle and these are expelled into some culture medium. Portions can be sent for histology and the remainder used for extraction of sperm in the IVF laboratory by stripping the seminiferous tissue out of the connective tissue membrane of the seminiferous tubule.