Charles T. Faulkner wrote:
> I have seen studies that
> purport to have increased sensitivity for detecting Giardia by
> sedimentation compared to ZnSO4.
I recall during the development phase of our (LMD) ELISA for Giardia
results that indicated spun samples yielded better results than non-spun
samples. We summized the concentration of free Ag was the reason, but
this is not significant because of the way in which a commercial ELISA
> I don't really believe it based on my
> experience, and I suspect that if this was really true there would not be
> the proliferation of ELISA and IFA based techniques to assist one with
> identification of Giardia, and Cryptosporidium.
Two reasons for going to test methods like ELISA are: 1) cost and 2)to
help eliminate errors in identifying organisms by less skilled eyes. Our
(LMD) tests were 'built' to be very forgiving of poor technician
technique yet give accurate results. Even IFA requires a knowledgable
operator to id the right bug and not falsely id x-reactions (like with
algae) and there is the equipment cost of IFA. Most X-reactions with
ELISA are usually worked out in the products R&D stage. But you use the
one you like and the one you get your best results with for in the end
it is the accuracy of your decision that counts to your doc and pt.
PS Making a good commercial ELISA is more an Art than it is a Science.
L. Mau, Biologist
PATHOGENIX Laboratories & Technologies
431 Country Club Lane, Suite 100
Coronado, CA 92118 USA
email: jimmau at pathogenix.com
Technologies for the Health of the Human Environment