Ken-
This was when using 14C iodoacetate, as a post-doc in Stockholm. We kept
an aqueous stock of neutralized iodoacetic acid (+ 1 equivalent of NaOH) in
the freezer, together with ~0.5ml chloroform, making a 2 phase system with
chloroform on the bottom. The iodine is more soluble in chloroform and
turns it pink. Aliquot from the top. I think this was a widely used
trick, but I'm not sure (it would be interesting to know). In any event,
we never had any problems, and we used to use that scheme here as well.
Since abandoning label and switching to NIPIA (N-isopropyliodoacetamide),
which seems to have much better storage characteristics, we've quit using
the chloroform routine.
Regards,
John Hempel, PhD Ph (412) 624 0161
University of Pittsburgh FAX (412) 624 4759
Department of Biological Sciences
Pittsburgh PA 15260 email: hempel@psc.edu