Oxazine 1 perchlorate is a symmetric cationic dye (λ_ex=653 nm, λ_em=666 nm). In Vitro: Oxazine 1 perchlorate (OX1) absorbs and emits light at about 653 and 666 nm in dilute aqueous solutions, respectively. It is soluble over a very wide range of polar solvents. The optical spectrum of Oxazine 1 perchlorate typically possesses an intense absorption band (λ_max), which is neighbored by a shoulder at shorter wavelengths. Oxazine 1 perchlorate appears to exist almost in its monomeric form at concentrations below about 1×10^-4 M in aqueous solutions. As it is expected, similar to polar ordinary liquid solvents, Oxazine 1 perchlorate shows only single fluorescence band in polar anisotropic media^[1].