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.
Composition of degenerate pools. Boldface lettering indicates positions that differed from wild type. R indicates any purine, W indicates T or A, Y indicates any pyrimidine, and N indicates any nucleotide. The core PPT is shaded, and the T stretch is boxed. The vertical line indicates the site of wild-type plus-strand primer cleavage.
