A Comparison Of Iron Histochemical Methods For Use On Glycol Methacrylate Embedded Tissues

Four histochemical tests for iron and four procedures for its removal were investigated in regard to their suitability for glycol methacrylate embedded tissues. The HCl-ferrocyanide and chlorate hematoxylin methods were easily modified for plastic sections. The latter does not use iron-containing reagents. Desiderization was complete both after a fifteen minute exposure in 1% Na₂S₂O₄ in 0.1 M acetate-HCl buffer (pH 4.5) and, if an acid method is preferred, after twelve hours in 5% oxalic acid. A six hour treatment in 3.7 N H₂SO₄ also removed all histochemical iron but was accompanied by a relatively greater loss of tissue basophilia.