[Histonet] Nonspecific staining in enterocyte cytoplasm

[Mikael Niku]

Dear Histonetters,

I'm looking for an explanation for a peculiar type of nonspecific 
staining in the small intestine: with several monoclonal antibodies, we 
get intensely stained granules or vacuoles in the enterocyte cytoplasm, 
quite specifically localizing at a small area on the apical side of the 
nucleus. The nucleus itself, the most apical cytoplasm and the plasma 
membrane are clear.

The staining appears to depend on the primary antibody, but occurs with 
several presumably independent monoclonals which otherwise work fairly 
nicely. It is somewhat exaggerated by alkaline antigen retrieval but 
unaffected by biotin or peroxidase blocking. We are routinely using a 
serum block, and include BSA in the antibody dilutions, but haven't 
tried other blocking methods against nonspecific antibody binding so far.

This is about paraformaldehyde-fixed paraffin sections of bovine tissues.

With best regards, Mikael

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  Mikael Niku             URL: www.helsinki.fi/~mniku/
  University of Helsinki  Dept. Basic Veterinary Sciences

  - Mitäkö mieltä olen länsimaisesta sivistyksestä?
  Minusta se olisi erinomainen ajatus!                                                        
                                          - Gandhi

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