the EDTA buffered to pH 7?
as an acid decalcifier as well as a chelator. In this case, assuming your stain still works and will not be affected by acid pH, change to 10% formic acid, which provides much faster decalcification. Check the endpoint (when all the calcium is gone) daily. [ But see Answer 1 for acid-sensitivity of galactosidase. ] If you have checked the endpoint and all the calcium is gone, rinse the tissue in water for at least 8 hours to remove all the excess EDTA before putting it in alcohol. Simon Smith (smiths5[AT]pfizer.com) Answer 3. (A formic acid procedure for teeth, with oxalate testing) The protocol we use here at Ind. Univ. School of Dentistry is as follows: The protocol we use here at Ind. Univ. School of Dentistry is as follows: After teeth are fixed in 10% neutral buffered formalin, they are placed in wide mouth bottles with a 5% formic Acid solution. They are then checked each day by pipetting 5 ml of the acid solution into a test tube to which 1 ml of 2.5% ammonium oxalate is added.