Dear Histonetters,

I am in need of a recipe for a citrate-phosphate buffer solution that is
used with a saturated aqueous ammonium oxalate solution for end point
determination of EDTA decalcified specimens.  I have a article that
describes this method but it neglects to give the amounts needed to make up
the buffer.

This procedure calls for 0.5 ml of spent EDTA solution to be mixed with 1.0
ml of citrate-phosphate buffer and 2.5 ml of saturated aqueous amonium
oxalate.  If calcium is present in the test tube, a cloudy white precipate
will form.  A clear solution after 20 minutes indicates the absence of
detectable calcium in the decalcifying solution.

Or, does any one have another tried and true procedure for EDTA end point
testing?

Thanks so much, again.

Rose Bellantoni