I want to measure ceruloplasmin according to Schoslnsky, 1974. I tried o-dianisidine to replace o-dianisidine dihydrocholride but it did not work, Can I try it again with a more acid pH acetate buffer?
You need to use the correct buffer and check the pH after you added the o-dianisidine. If you have the same correct pH, both compounds should lead to the same results. Acetate buffer of pH 5.0 is used in this assay. You may try to adjust your o-dianisidine solution with glacial acetic acid to pH 5.0. Mixing buffers or solutions with the wrong pH does not work in most cases.