The Histochemical Demonstration of Hemoglobin in Blood Cells and Tissue Smears

The demonstration of intracellular hemoglobin in permanent preparations has long been a problem. The affinity of hemoglobin for iron hematoxylin is well known but this stain also colors yolk, chromatin, and other structures and is therefore not a reliable criterion. The presence of hemoglobin has been associated with an acidophil cytoplasm which stains a characteristic color, but a careful inspection of living cells in early hematopoetic or embryological stages demonstrates that hemoglobin is present in the erythrocytes which are quite basophilic. In the course of some research on the blood of embryonic frogs it became desirable to demonstrate the presence of hemoglobin in cells by means of a specific staining reaction.