They grew the virus in monkey cell cultures, they purified the virus because you got to get all the other stuff from the cells that you're growing it in a way, they inactivated it by treating it with formalin which is just a formula-- it's just a mixture of Formaldehyde; Formaldehyde cross links proteins.

研究人员将病毒种植在猴细胞内,进行培养,并提纯病毒,在某种程度上,通过这种方法,可以得到所有类型的病毒,研究人员用福尔马林,处理病毒,使其灭活,福尔马林就是甲醛的水溶液,甲醛可以使蛋白质发生交联反应

耶鲁公开课 - 生物医学工程探索课程节选

Formaldehyde cross-links proteins, so, if you treated this virus with Formaldehyde, even it was able to enter a cell, it couldn't break down anymore.

甲醛使蛋白质发生交联反应,因此,如果你对病毒使用了甲醛,即使它可以侵入细胞,它也不能够再进行分解

耶鲁公开课 - 生物医学工程探索课程节选