[Histonet] Re: cleaved caspase(active)

[Cheryl Cross]

Hi Carl -

Not sure I can be of any help...but one thing I've found (and one  
reason I trust Cell Signaling's ab) is that I use thymus as my  
positive control and I get nice staining in the thymic (and lymph  
node) medulla in cells that often have a shrunken, dense nucleus (ie  
look microscopically apoptotic). When I tried another antibody  
positive staining was "willy nilly" if you will - endothelial cells,  
scattered circulating leukocytes, and then many many lymphocytes  
within the thymic cortex and medulla - i just did not trust that all  
those cells were apoptotic in a healthy control!

CC

Cheryl Cross, DVM, Dipl. ACVP
Researcher
University Corporation for Atmospheric Research
College of Veterinary Medicine
University of Tennessee Department of Pathology
2407 River Drive, Room A201
Knoxville, TN 37996-4542
(423) 967-2724
fax: 865-974-5616
ccross <@t> ucar.edu





On Sep 10, 2007, at 3:58 PM, Carl Hobbs wrote:

> A final question, after a preamble:
>
>
> I use Cell Signalling's, Biocare's and Abcam's anti Cleaved caspase  
> 3 ( "active"   : I always add that bit in, just in case;-), on pwax  
> sections after Citric acid HIER pH6 ( no other retrieval method/nor  
> omission works, for me )
>
> For me, the first Ab is too variable; works very well, sometimes.
> The second works most of the time, except that  I am worried that  
> the number of positive cells makes me think that non-cleaved  
> caspase 3 is demonstrated. ( in serial sections, Biocare's Ab gave  
> nuclear positivity that was absent, repeatedly, with the other two,  
> when I judged them to be working well
> ....there appeared to be a worrying co-positivity with Ki67....is  
> this possible?)
> The third Ab tends to be consistent BUT , again, demonstrates less  
> cells than the Biocare Ab. As does the Cell Signalling Ab, when it  
> works.
> Final Q: Finally....has anyone actually compared the available anti  
> CC3 ( active ;-)Abs to check for fidelity????
> Any comments on these comments of mine would be gratefully recd.
> Yep..the only consistency in my comments is inconsistency!
> Curious Carl
>
>
>
>
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