[Histonet] non-specific cross reactivity with mucus

[Jonathan Wilson]

Hello,
    I work with fish in a resarch lab and with some of the antibodies I use 
I get what I would consider non-specific crossreactivity with mucus either 
covering the body surface or in mucocyte granules. More often this problem 
would arise with rabbit polyclonal anti-peptide antibodies using neat serum. 
I usually get around this by affinity purifying using the peptide but in 
some cases this is not possible.
    Someone once told me that mucoproteins have a large number of antigenic 
determinants increasing the likelyhood of crossreactivity but I could never 
find a reference. I've searched through the archives but couldn't find an 
explanation except for a suggestion that it might be charge related. Could 
someone please shed some light on this situation for me. It is something 
that has bugged me for the longest time.
Thank you for any insight.
Sincerely,
Jon