>Who has experience in detection of Nisin in Food?
Actually the agar diffusion method of Delves-Broughton is a very
sensitive method for the detection of nisin in food.
An immunological method was developed by Applied Microbiology, Inc.
but I doubt if it was published. An Elisa method would be easier
(possibly more sensitive) than the agar diffusion method (which, as
described, is actually quite cumbersome). However raising antibodies
to nisin (even though it is a 34 amino acid peptide) is not trivial
and to my knowledge was done but once in a sheep in the U.K. (not
If you go higher tech with HPLC methods or LC-MS (possible the best)
be advised that nisin does degrade over time (especially at higher
pHs) but some of the degradation products remain active (so the
bio-assay over reports the amount of intact nisin).