Astrophloxine

• CAT Number: R011655
• CAS Number: 14696-39-0
• Molecular Formula: C27H33IN2
• Molecular Weight: 512.47
• Purity: ≥95%
• Synonyms: (2Z)-1-ethyl-2-[(E)-3-(1-ethyl-3,3-dimethylindol-1-ium-2-yl)prop-2-enylidene]-3,3-dimethylindole;iodide
• InChI: InChI=1S/C27H33N2.HI/c1-7-28-22-16-11-9-14-20(22)26(3,4)24(28)18-13-19-25-27(5,6)21-15-10-12-17-23(21)29(25)8-2;/h9-19H,7-8H2,1-6H3;1H/q+1;/p-1
• InChIKey: LGRNGKUSEZTBMB-UHFFFAOYSA-M
• SMILES: CCN1C2=CC=CC=C2C(C1=CC=CC3=[N+](C4=CC=CC=C4C3(C)C)CC)(C)C.[I-]

Astrophloxine is a fluorescent imaging probe capable of targeting antiparallel dimers. Astrophloxine can be used to detect aggregated Aβ in brain tissue and cerebrospinal fluid samples of Alzheimer’s disease (AD) mice[1].
Astrophloxine binds Aβ dimers with stronger fluorescence intensity (A.U.) than binding Aβ monomers[1].
Protocol for CSF analyses[1]:
1.Prepare 1 μL of CSF samples with 1 μL of 10X protease inhibitors and diluted the mixture with 8 μL of binding buffer. Binding buffer (0.1 M sodium phosphate, 0.15 M sodium chloride, 10 mM EDTA; pH 7.2).
2.Dilute Astrophloxine to 0.5 μM with binding buffer.
3.Add individual samples and dye to the wells of a 96-well half-area black microplate with a sample to dye ratio of 1:3.
Detect at λex=540 nm/λem=570 nm.
Astrophloxine shows more fluorescence (A.U.) in APP/PS1 mice CSF rather in WT mice, and is able to indicate soluble Aβ oligomers in CSF and insoluble plaques in brain tissue[1].

Reference

[1]. Lee JC, et al. Discovery of Chemicals to Either Clear or Indicate Amyloid Aggregates by Targeting Memory-Impairing Anti-Parallel Aβ Dimers. Angew Chem Int Ed Engl. 2020 Jul 6;59(28):11491-11500. 
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