Brilliant Blue G is a synthetic triarylmethane dye primarily used in laboratory and medical applications. It serves as a biological stain in microscopy to visualize cells, tissues, or the internal limiting membrane. Employed in gel electrophoresis as a dye for protein staining or as a tracking indicator. In ophthalmology, it is used during vitreoretinal surgery to stain and visualize the retina and internal limiting membrane, aiding in surgical precision. Additionally, it functions as a gap junction blocker in neuroscience research to study cell communication.