Metachromasia induced by inositol-hexa-phosphate with toluidine blue

Abstract

1. Metachromasia with toluidine blue could be induced by inositol hexaphosphate, the smallest chromotrope molecule so far reported. 2. The metachromatic compound, pink in color, and distinct from orthochromatic dye, could be separated by centrifugation. This complex could as well be decomposed by dil. HCl. 3. The stoichiometry of the metachromatic complex has been studied and the molar ratio of dye: phytate has been shown to vary with varying proportions of dye and phytate used in the reaction mixture and a maximum value of 10 could be obtained suggesting a steric hindrance for the attachment of dye to the phytate-molecule. 4. The divalent cations like, Ba⁺⁺, Mg⁺⁺, and Mn⁺⁺ interfered with the formation of metachromatic complex, possibly competing with the dyes for the anionic sites of the phytate molecule.