Gill-III hematoxylin is another variant of the Gill hematoxylin staining methods developed by Dr. Richard W. Gill. Gill-III is also used to stain cell nuclei and basophilic structures in tissue sections.
The main difference between Gill-III and the other Gill hematoxylin methods (Gill-I and Gill-II) is the concentration of hematoxylin in solution. Gill-III is more concentrated than Gill-II and than Gill-I, resulting in staining with stronger intensity. As with the other Gill stains, Gill-III is often used in combination with eosin or other contrasting dyes to provide differential visualization of tissue structures, similar to hematoxylin-eosin (HE) staining.