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.
Tracheal progenitor clone types. (A) Tracheal progenitor cells growing on an irradiated NIH3T3 fibroblast feeder layer. Giemsa stain. Arrows indicate rimmed clones. (B) Phase-contrast image of a non-rimmed clone. (C) Phase-contrast image of a rimmed clone. The rim domain is indicated by the arrows. The cobblestone domain is located in the center of the clone.
