Fig. 1.
Negative contrast electron micrographs (uranyl acetate) of virus particles. Bar, 100 nm. (a) Open form of the large particle (citrus psorosis virus), and (b) collapsed form (freesia sneak virus) (courtesy of R. G. Milne).
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.