A red dye
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Phloxine B

Item No. 18675

Product Insert (PDF)Safety Data Sheet (SDS) (PDF)
Technical Information
Formal Name
2',4',5',7'-tetrabromo-4,5,6,7-tetrachloro-3',6'-dihydroxy-spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one, disodium salt
CAS Number
18472-87-2
Synonyms
  • Acid Red 92
  • Cyanosine
  • D&C Red No. 28
Molecular Formula
C20H2Br4Cl4O5 • 2Na
Formula Weight
829.6
Purity
≥95%
Formulation (Request formulation change)
A crystalline solid
Solubility(Learn about Variance in Solubility)
DMF: 30 mg/mlDMSO: 30 mg/mlEthanol: 2 mg/mlPBS (pH 7.2): 10 mg/ml
λmax
551 nm
SMILES
BrC1=C([O-])C(Br)=CC2=C1OC3=C(Br)C([O-])=C(Br)C=C3C24C(C(Cl)=C(Cl)C(Cl)=C5Cl)=C5C(O4)=O.[Na+].[Na+]
InChi Code
InChI=1S/C20H4Br4Cl4O5.2Na/c21-5-1-3-17(9(23)15(5)29)32-18-4(2-6(22)16(30)10(18)24)20(3)8-7(19(31)33-20)11(25)13(27)14(28)12(8)26;;/h1-2,29-30H;;/q;2*+1/p-2
InChi Key
OOYIOIOOWUGAHD-UHFFFAOYSA-L
Shipping & Storage Information
Storage
-20°C
Shipping
Room temperature in continental US; may vary elsewhere
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    Product Description

    Phloxine B is a red dye, the USP grade of which is used as a color additive for food, drugs, and cosmetics.1 It has also been used as an alternative to Gram staining, to differentiate between Gram-negative and Gram-positive bacteria.2 At 100 µg/ml, it can inhibit methicillin-resistant S. aureus growth in vitro.3 Phloxine B has also been shown to modulate channel activity of wild-type cystic fibrosis transmembrane conductance regulator chloride channels (CFTR; Ki = 38 µM) and mutant delta F508 CFTR (Ki = 33 µM).4

    WARNING This product is not for human or veterinary use.

    References & Product Citations
    Product Description References

    1. Sabnis, R.W. Handbook of biological dyes and stains: Synthesis and industrial applications. (2010).

    2. Rasooly, R. PhloxineB, aversatile bacterial stain. FEMS Immunol. Med. Microbiol. 49(2), 261-265 (2007).

    3. Rasooly, A., and Weisz, A. In vitro antibacterial activities of phloxine B and other halogenated fluoresceins against methicillin-resistant Staphylococcus aureus. Antimicrob. Agents Chemother. 46(11), 3650-3653 (2002).

    4. Melin, P., Norez, C., Callebaut, I., et al. The glycine residues G551 and G1349 within the ATP-binding cassette signature motifs play critical roles in the activation and inhibition of cystic fibrosis transmembrane conductance regulator channels by phloxine B. J. Membr. Biol. 208(3), 203-212 (2005).

    Product Citations

    Zhang, B., Nesbitt, N.M., Pereira, P.J.B., et al. Biochemical characterization of biliverdins IXβ/δ generated by a selective heme oxygenase. Biochem. J. 477, 601-614 (2020).