[Histonet] Universal (protein) block for IHC

[Kelly D Mcqueeney]

Casein is the predominant phosphoprotein </wiki/Phosphoprotein> (80%) 
found in fresh milk. It is relatively </wiki/Milk>hydrophobic 
</wiki/Hydrophobic>, making it poorly soluble in water. That is why I 
suggest buying it. Even though I did see a decrease in specific 
staining, it's probably due to my prep of casein. Manufacturers have 
developed the perfect concentration (0.3 or 0.03%, I forgot) for 
blocking.  Best of luck!

Walters, Katherine S wrote:

>I thought casein was just a fancy name for skim milk.  I use it
>sometimes as an avidin block by making a 5% solution out of cheap dried
>milk.
>
>Kathy
>
>-----Original Message-----
>From: histonet-bounces <@t> lists.utsouthwestern.edu
>[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Kelly D
>Mcqueeney
>Sent: Wednesday, April 06, 2005 4:42 PM
>To: Johnson, Teri
>Cc: Histonet
>Subject: Re: [Histonet] Universal (protein) block for IHC
>
>Hi Teri,
>I noticed a decrease in specific staining when I plugged it into my 
>protocol. I made it myself and it was a big pain. Buy it! Try increasing
>
>antibody concentration on a few slides and see what happens. I never use
>
>a block with my secondary.
>
>Good luck!
>
>Johnson, Teri wrote:
>
>  
>
>>Has anybody converted to using a universal protein block (casein) for
>>their immunohistochemistry protocols rather than using species specific
>>normal sera?  For those who have made the conversion, did you have to
>>make any changes to your methodology or did you just plug it in to your
>>protocol and run?  Did you notice any difference in the staining
>>intensity for known antibodies (stronger, weaker, no change)?  Are you
>>also using it as a secondary antibody diluent or for washes?  Finally,
>>are you using commercially available reagent or are you making your
>>    
>>
>own?
>  
>
>>Thanks so much!
>>
>>
>>Teri Johnson
>>Managing Director Histology Facility
>>Stowers Institute for Medical Research
>>1000 E. 50th St.
>>Kansas City, Missouri  64110
>>tjj <@t> stowers-institute.org
>>
>>
>>
>>_______________________________________________
>>Histonet mailing list
>>Histonet <@t> lists.utsouthwestern.edu
>>http://lists.utsouthwestern.edu/mailman/listinfo/histonet
>> 
>>
>>    
>>
>
>_______________________________________________
>Histonet mailing list
>Histonet <@t> lists.utsouthwestern.edu
>http://lists.utsouthwestern.edu/mailman/listinfo/histonet
>
>
>  
>