FD&C Blue #1 as indicator of ingestion

[Martin E. Feder]

I am attempting to use a food coloring agent, FD&C Blue #1, to measure 
feeding rates in Drosophila larvae.  This dye does not pass the gut 
wall and can therefore be used as an indicator of food consumption.  
The protocol I am using requires FD&C Blue #1 in its pure (i.e., 
powdered) form.  Most sources at the wholesale and retail level sell a 
blue food color solution, which is FD&C Blue #1 dissolved in a mixture 
of liquids.  Obviously these sources buy the powder from a supplier, 
and then dissolve it for wholesale or retail sale.  My question is: Do 
you have names/addresses/phone #s for any of the original 
manufacturers of FD&C Blue #1?

I would appreciate any information you can provide.  Thanks in 
advance.

Dr. Martin E. Feder
Professor
Department of Organismal Biology & Anatomy
The University of Chicago
1027 East 57th Street
Chicago, IL 60637 USA
E-Mail: m-feder at uchicago.edu
Telephone: 312 702-8096
Fax: 312 702-0037
http://www.bsd.uchicago.edu/BSDinfo/FacInfo.cgi/Feder/Martin