Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The activity of the HIV-1 PR (solid circles) and XMRV PR (open circles) were measured at increasing urea concentration, using an HPLC detection of the substrate cleavage as described in the Materials and Methods.
