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

In some cases that backbone gets methylated and those regions of the DNA that are methylated get treated differently by the cell than unmethylated regions.

一些情况下,主链会甲基化,该甲基化区域的DNA,和未甲基化区域的DNA,会被细胞区别对待

耶鲁公开课 - 生物医学工程探索课程节选