Sulforhodamine B Sodium Salt

• CAT Number: R031424
• CAS Number: 3520-42-1
• Molecular Formula: C₂₇H₃₀N₂NaO₇S₂
• Molecular Weight: 580.65
• Purity: ≥95%
• Synonyms: 3,6-Bis(diethylamino)-9-(2,4-disulfophenyl)-xanthylium Sodium Salt; [6-(Diethylamino)-9-(2,4-disulfophenyl)-3H-xanthen-3-ylidene]diethylammonium Hydroxide; C.I. Acid Red 52; AR 52; Acid Leather Red KB; Acid Red 52; Acid Red B-SF; Acid Red XB; Acid Rh
• Storage: -20°C
• IUPAC Name: sodium;4-[3-(diethylamino)-6-diethylazaniumylidenexanthen-9-yl]benzene-1,3-disulfonate
• InChI: InChI=1S/C27H30N2O7S2.Na/c1-5-28(6-2)18-9-12-21-24(15-18)36-25-16-19(29(7-3)8-4)10-13-22(25)27(21)23-14-11-20(37(30,31)32)17-26(23)38(33,34)35;/h9-17H,5-8H2,1-4H3,(H-,30,31,32,33,34,35);/q;+1/p-1
• InChIKey: SXQCTESRRZBPHJ-UHFFFAOYSA-M
• SMILES: CCN(CC)C1=CC2=C(C=C1)C(=C3C=CC(=[N+](CC)CC)C=C3O2)C4=C(C=C(C=C4)S(=O)(=O)[O-])S(=O)(=O)[O-].[Na+]

Sulforhodamine B Sodium Salt(CAT: R031424) is a bright red, water-soluble fluorescent dye commonly used in biological and biochemical applications. With strong absorbance around 565 nm and emission near 586 nm, it is ideal for fluorescence microscopy, flow cytometry, and quantitative cell proliferation assays—notably the SRB assay for measuring cellular protein content. Sulforhodamine B binds electrostatically to basic amino acid residues in fixed cells, enabling accurate colorimetric or fluorometric quantification. Its excellent photostability, low background signal, and high extinction coefficient make it valuable for imaging and detection in research involving live or fixed cells, drug screening, and toxicology.