Phenosafranin

green crystalline powder

Phenosafranin is a bacterial stain used in microscopy, biological stain, and nuclear staining.

ChEBI: Phenosafranine is an organic chloride salt having 3,7-diamino-5-phenylphenazin-5-ium as the counterion. It is commonly used for staining Gram negative bacteria red in smears to contrast with the blue Gram positive organisms. It has a role as a fluorochrome, a histological dye and a photosensitizing agent. It contains a 3,7-diamino-5-phenylphenazin-5-ium.

Phenosafranin (PSF) is a red dye released from cells with intact plasma membrane. PSF at lower concentration is used to stain mitochondria supravitally.

Phenosafranin is used to distinguish living from dead cells. A 0.1 % aqueous solution, it is taken up by dead or abnormal cells immediately, while living cells remain unstained for at least 30 min.

Crystallise the chloride from dilute HCl. It has UV with at 530nm in H2O. The picrate decomposes on heating and has a solubility of 0.0048% in H2O at 18o. [Beilstein 23 H 395, Beilstein 25 H 394, 25 I 654, 25 II 338, 25 III/IV 3050.]