Bradford Protein Assay

Dima Klenchin klenchin at
Sat Mar 10 22:44:08 EST 2001

jhaines at (Jeffery Haines) wrote:
:Three questions:
:1.  Is the Bradford protein assay specific in determining correct protein 
:content when the experimental solution contains many glycoproteins? (in 
:comparison to the bovine serum albumin standard?) 

No, it is not. _All_ proteins bind Coomassie differently. BSA 
standard is valid only of you have determined correction 
coefficient by also measuring concentration of your protein
by some other, truly specific method (ideally, aa analysis
or BCA assay in all other cases). 

:ie. could there be less 
:dye binding, therefore incorrect protein determination due to 
:glycosylated proteins?

Yes, there could. 

:2.  What is the difference between Coomassie Brilliant Blue G-250 and 
:Coomassie Brilliant Blue R-250?

One methyl group is the difference. As a result, R-250 does not
form colloids readily.

:3.  Currently I a accessing this board through a basic TELNET system... 
:which can be extremely frustrating... is there any way to hook it up to 
:the netscape newsgroup program? 

Chances are your campus has newsserver that you can access
directly with a newsreader (netscape is not the best choice
of them, btw). Find out what the address of the newsserver
the machine you telnet into connects to, and simply plug 
the IP in your newsreader of choice (omit user/password).
If for some reason this does not work, you have many other 

   If you pay for any ISP, chances are an access to 
Usenet is included - ask them for the address. 
   Or you can search for "public newsservers" and choose
one that allows posting. See, for example,
   Also, there are a number of free web-based Usenet 
(I am familar with because my daughter
uses it; it's free and OK). 
   Finally, there is a really inconvenient and archaic way
of doing it supported by (basically, mail-to-news;
read the FAQ there).

: Dima if you're reading thanks for all of the help you have given me thus far!
: -- you're truly an asset to the board.

Thanks. I am trying.

        - Dima

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