Improved beta-Gal substrate

Duncan Clark Duncan at
Fri Nov 19 15:07:34 EST 1993

In article <Mark_Solomon-071193121124 at> Mark_Solomon at writes:

>I have recently read about an improved substrate for assaying
>beta-galactosidase activity, CPRG (chlorophenol
>red-beta-D-galactopyranoside).  The higher extinction cooeficient of the
>cleaved product makes it about 10 times as sensitive as ONPG. 
>Unfortunately, it is much more than ten times as expensive, at least from 
>Boehringer Mannheim.  I was wondering if anyone knows of a source of this
>reagent for less than ~$50/250 mg.  Thanks

Sorry about the delay in replying to this but I only found out the answer
today. CPRG-Gal is patented by Boehringer so at present is only available
from them. I understand that a close alternative is one called MNP-gal. I
don't know what the MNP stands for but do know that this is water soluble,
red chromophore, high extiction coefficient and supposedly cheaper.

I promised some while ago to post a complete list of B-galactosidase 
chromogenic Gal substrates. Unfortunately I am still waiting for the list
from a manufacturer. They are rewriting their literature hence the delay.
I will post once I have it.


Duncan Clark                        | Internet:    duncan at
GeneSys Ltd.                        | Compuserve:  100015.1406 at

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