Introduction

BioGnost’s Hem Diff is a weak differentiation reagent used in modified regressive hematoxylin-eosin (HE) staining (using Hematoxylin G2, G3, ML), in both automated and manual staining procedures. Modified regressive staining refers to a method that includes overstaining of structures and subsequent removal of excess dye from the cytoplasm, differentiation of nuclei with a weaker differentiator, and better binding of eosin. The use of a weak differentiator in modified regressive staining is also necessary due to the removal of excess blue dye from the slides, a phenomenon that occurs mostly due to the vertical position of the slides during HE staining in automatic stainers where the specimens are immersed in a reagent container. A weaker differentiation reagent enables longer incubation and more precise differentiation. Regardless of the fixative in which the tissue is fixed (formalin or glyoxal), Hem Diff gives clear results. The time required for differentiation with the Hem Diff reagent is the same regardless of the fixative used to fix the examined sample.