When a virus enters the cell, it releases its genetic material, some of which can be detected by OAS. When this occurs, a molecule containing a particular sequence of nucleotides (2’-5’-oligoadenylate) is produced. This short chemical can then interact with RNase L. Normally, the enzyme is inactive or latent (thus the L). But as soon as contact is made, there’s an activation that turns the quiet floater into a chopping machine. If a single stranded RNA molecule is found, it’s degraded and soon will be destroyed.