An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
LaFrance-Corey RG, Howe CL.LaFrance-Corey RG, et al.J Vis Exp. 2011 Jun 13;(52):2747. doi: 10.3791/2747.J Vis Exp. 2011.PMID: 21694694Free PMC article.