HE staining
HE staining (or H&E) is the most widely used stain in medical diagnosis. Hemalum, a complex formed from aluminum ions and hematein, stains acidic structures (negatively charged) such as nuclei and some other cell components blue. A second stain follows the nuclear-staining, the E in H&E. Eosin is an acidic dye that likes to connect to basic structures and stains the cytoplasm and extracellular proteins pink.