An official website of the United States government
Here's how you know
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.
Determination of chromosome numbers in mouse embryonic fibroblasts (MEFs). Karyotyping was performed 1 day after seeding in early passages (P20; a–c) and late passages (P50; d–f) MEFs. Spreads from 100 cells were examined per genotype.