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.
Images displaying (A) the lowest color intensity (grade 3F), (B) the largest color gradient (grade 1 CHR), and (C) the best color intensity with the most uniformity (grade 1 CHR). The color generated inside the channels (C) is attributed to excess color reagent spotted on detection zone.
