We have found that DAB (3-3-diaminobenzidine) could induce a strong
fluorescence signal in nervous tissue.
The tissue has been fixed in paraformaldehyde, however we could
ensure, that the fluorescence signal is not due to a
formaldehyde-induced fluorescence (FIF) of monoamines (like serotonin
etc).
Subsequent controlls showed also that the fluorescence is not induced
by H2O2.
Has anybody an idea, if DAB could react with a substance (in nervuos
tissue or in any tissue) forming an complex or induce a reaction, that
may provoque this fluorescence ?
(the only thing I have found in literature is, that DAB is also used
to induce fluorecence in photosystem I and II in cloroplasts)
If anyone has got an idea or a hint, I would be very glad to receive
an answer
