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.
Dendrogram displaying the level of agreement of ELISA-determined antibody concentrations among 12 laboratories. One laboratory evaluated the series twice. Laboratories denoted with an asterisk submitted three or more assay determinations for each serum sample. These values were averaged prior to generation of the dendrogram.
