5,5'-((1E,1'E)-1,4-phenylenebis(ethene-2,1-diyl))bis(2-hydroxybenzoic acid)

X-34 is a lipophilic and bright yellow-green fluorescent derivative of Congo red (HY-D0236). X-34 can be used to stain neuritic and diffuse plaques, neurofibrillary tangles (NFTs), neuropil threads, and cerebrovascular amyloid in the brain. X-34 can be used for research of Alzheimer’s disease[1].

Fluorescent, amyloid-specific dye', 'X-34 (1,4-bis(3-carboxy-4-hydroxyphenylethenyl)-benzene) is one among the small-molecule γ-secretase modulators (GSMs) involved in lowering Aβ42 levels (the 42-residue isoform of the amyloid-β peptide). X-34 has also been used to visualize intracellular immunoreactive deposits with classic amyloid fibrillar ultrastructure in living transgenic Caenorhabditis elegans animals. It is also used as a histochemical stain for determining pathological changes in Alzheimerμs disease (AD).', 'X-34 is a fluorescent, amyloid-specific dye. It binds at a different site than Pittsburgh Compound B and is a highly fluorescent marker for beta-sheet structures.

X-34 is a lipophilic and highly fluorescent marker used to examine pathological changes in Alzheimer’s disease (AD). This cellular dye was developed as a derivative of Congo red to be more compatible with in vivo applications. By replacing the azo groups (nitrogen-to-nitrogen double bonds) in Congo red with carbon-to-carbon double bonds and having more lipophilic salicylic acid groups, X-34 has proven to be highly fluorescent and have increased membrane permeability. X-34 detects β-sheet structures and labels amyloid plaques, neurofibrillary tangles (NFTs), neuropil threads, and vascular amyloid in AD brains.