Dear All,
This is to any ELISA buffs out there!
We have an in-house ELISA for IL8. We've found that the capture
monoclonal binds recombinant IL8 standards in a pH dependent fashion with
the signal rising from ph7.5 to a maximum at ph5-6. We are using the
assay to measure the cytokine in urine and find that the drop in signal
can by abolished by dialysing all the salts (Na, K, Cl HCO3 principally
plus urea) out of the urine and reinstated by replacing them. So we
decided to correct down the pH of samples and to make this easier decided
to use a universal indicator from BDH to spot the more neutral samples so
we could correct them with HCl. Strangely, the indicator seems to restore
the signal just as well as dialysis! Do any of you understand this or do
you know a smart chemist who might?
Any suggestions gratefully received either in this newgroup of by email
to A.Finn at sheffield.ac.uk
Thanks
Adam Finn
