Introduction

Neutral Red reagent is intended for use with various staining methods in histology and cytology. It is primarily used as nuclear stain as dye for nuclei and basophilic structures, but it can also be used as fluorochrome dye. It is used for supravital staining, as counterstain during Gram staining, for staining Nissl bodies, and as a part of Twort’s histology dye for polychromatic staining. Neutral Red dye is also a pH indicator that changes color from red to yellow with 6.8 to 8.0 pH range.