Longest human tau isoform that stabilizes axonal microtubules; its misfolding and aggregation drive neurodegenerative tauopathies. Recombinant full length human tag-free Tau-441 was expressed in E. coli cells. Molecular Weight ~64 kDa. Supplied as sterile 50 mM Tris-HCl pH 7.5, 50-300 mM NaCl, 1 mM DTT, 10-25% glycerol. Store product at –70°C. For optimal storage, aliquot target into smaller quantities. Avoid repeated handling and multiple freeze/thaw cycles.