X-34

• CAT Number: I040633
• CAS Number: 215294-98-7
• Molecular Formula: C24H18O6
• Molecular Weight: 402.40
• Purity: ≥95%
• Synonyms: 5-[(E)-2-[4-[(E)-2-(3-carboxy-4-hydroxyphenyl)ethenyl]phenyl]ethenyl]-2-hydroxybenzoic acid
• InChI: InChI=1S/C24H18O6/c25-21-11-9-17(13-19(21)23(27)28)7-5-15-1-2-16(4-3-15)6-8-18-10-12-22(26)20(14-18)24(29)30/h1-14,25-26H,(H,27,28)(H,29,30)/b7-5+,8-6+
• InChIKey: MCBNOAYTZBUCSX-KQQUZDAGSA-N
• SMILES: C1=CC(=CC=C1C=CC2=CC(=C(C=C2)O)C(=O)O)C=CC3=CC(=C(C=C3)O)C(=O)O

X-34(CAT: I040633) is a lipophilic, fluorescent derivative of Congo red designed for the sensitive and selective staining of amyloid pathology. Exhibiting bright yellow-green fluorescence, X-34 effectively labels neuritic and diffuse plaques, neurofibrillary tangles (NFTs), neuropil threads, and cerebrovascular amyloid in brain tissue. Its high binding affinity for β-sheet-rich structures makes it an essential tool in Alzheimer’s disease research and other neurodegenerative disorders involving protein aggregation. X-34 enables both in vitro histological analysis and in vivo imaging applications, providing detailed visualization of amyloid pathology.