In that case, we took the gene for the Hepatitis B protein.

在此种情况下,我们将乙肝病毒的基因同蛋白质外壳分离

耶鲁公开课 - 生物医学工程探索课程节选

And they did that by intentionally infecting calves, by harvesting their skin when they were at a certain point of the disease, and by isolating the virus from the skin of the calves.

他们有意感染很多小牛,当小牛疾病发展到一定程度,就收割牛皮,然后把病毒从牛皮里分离出来

耶鲁公开课 - 生物医学工程探索课程节选

You'd want to make sure that you separated the virus from all the other parts of cow skin so that your ultimate preparation was enriched in the virus and didn't contain quantities of other things that would be hazardous.

你要保证,你从所有的牛皮组织上分离出病毒,这样最终的制剂产品才会富集病毒,并且不会携带其它物质,这些物质可能带来危险

耶鲁公开课 - 生物医学工程探索课程节选