Frozen Pertussis Toxin? - (Sep/08/2009 )

Unfortunately someone has frozen our reconstituted pertussis toxin (just dissolved in sterile Buffer). As it is said in the data sheet pertussis looses its activity after freezing. I need the pertussis toxin for eae immunization. Does anyone know if the thawed protein still has enough activity for immunostimulation or how I can determine activity without using hamster ovary cells?

Can you do cAMP assays in your lab (or other friendly lab). A respiratory/ pharmacology lab colleague may be willing to measure cAMP release in the presence and absence of pertussis. If not HOCs, then use bronchial tissue.

If you run a gel, do you get split bands (implying breakdown). Absence of bands doesn't neccesarily mean functioning toxin, of course.

Last one, perhaps the supplier would take some of your frozen pertussis and run it on their in-house assay.
Interesting problem.