direct blue1

Direct Blue 1 (Pontamine sky blue), a counterstain for background autofluorescence in immunofluorescence histochemistry, structurally resembles glutamate and operates as a potent, competitive VGLUT inhibitor, not impacting plasma membrane transporters. This compound stands out as the inaugural small molecule PrP ligand to inhibit Aβ binding.

Diphenyl Blue (Direct Blue 14) (Direct Blue 14) is used as a dye for a group of azo dye.

Direct Blue 108, a triphenyl two oxazine compound, is utilized for dyeing cotton, viscose fiber, silk, and their blended fabrics [1].