A patent held by veterinary physiologist ralph brinster of the university of pennsylvania describes how a man with a " deleterious genetic trait " would first have a testicular biopsy to remove some of the primitive cells that develop into sperm 宾夕法尼亚大学兽医生理学家拉尔夫?布林斯特拥有的一项专利是，首先对携带“有害基因序列”的男子进行睾丸活组织检查，取出一些会生长成精子的原始细胞。
