[Histonet] caspase 3 and background staining

[CCross6032 <@t> aol.com]

Hi everyone - I see that there are several successful caspase 3 protocols in 
rodents running; my question is - in my control tissues the respiratory 
epithelium, and interstitial cells of the lung (they look like histiocytes 
microscopically) light up; i am looking primarily at the heart and there is an 
acceptable level of background for interpretation (in my opinion anyway :) ). I have 
done searches and cannot find if these are normal regions to light up - if so, 
why? we are using the active caspase 3 antibody and the Dako envision system. 
any references as to the normal caspase 3 positive cells would be great! thank 
you!

Cheryl Cross
UTCVM