Testicular biopsy is when men get a portion of their testes removed to be scientifically tested, often for reproductive reasons. The Torah prohibits Jews having marriage with eunuchs, men with injured genitals. So would a Jewish man who got testicular biopsy be fine to marry?
The restriction is specific to males who have suffered an actual loss of reproductive organs. Even then, the restriction is not considered universally binding in all scenarios as such a Jew can marry others outside of the main marriage pool.
- They may marry converts
- They may marry women unable to have children themselves
If a man loses only a part or one of his testicles, he isn't restricted from marriage as long as he still has his reproductive capacity intact.
The fact is though this person would need to make the issue fully disclosed as part of the shidduch process so the woman is aware he may have reproductive issues. Losing a testicle may not make someone sterile but knowing that there was an issue may present more information to the woman deciding on a husband.
It would benefit a male in such a situation to seek out a reproductive screening to verify with medical records that he is still fit to produce children. That would go a long way in easing concerns regarding his injury.
דין פצוע דכא וכרות שפכה ובו יד סעיפים: פצוע דכא וכרות שפכה אסורים לישא ישראלית ומותרים בגיורת ומשוחררת ואפילו כהן שהוא פצוע דכא מותר לישא גיורת ומשוחררת לפי שאינו בקדושתו ואפילו נתינה או אחד מהספקות מותרת לו הואיל ופצוע דכא אסור לבא בקהל לא גזרו על הנתינים ולא על הספיקות אבל אסור בממזרת ודאית שהרי אסורה מן התורה ויש מתירים אפי' בממזרת (טור והראב"ד והרשב"א):
A petzua daka and a krus shafcha [each of these are categories of males with reproductive losses/problems] are prohibited to marry a jewess, and permitted with a convertess and a freedwoman. And even a priest who is a petzua daka is permitted to marry a convertess and a freedwoman, since he is not in his sanctity. And even a nesina or one of the questionables are permitted to him; since a petzua daka is forbidden to enter the congregation, they did not decree on him regarding nesin's nor regarding questionables. However, he is forbidden in an unquestionable bastardess, for behold she is forbidden from the Torah. And some permit even a bastardess. (Tur, and Raavad, and Rashba)