Metachromasia inhibiting components in amyloid

I): The degree of inhibitory effect of serum proteins and a periodic acid Schiff-positive amyloid fraction on metachromasia resulting from a metachromatic amyloid fraction was studied and compared to the metachromatic potency of chondroitin sulfate exposed to the same type of inhibition. The metachromatic properties of chondroitin sulfate were close to those of the metachromatic amyloid fraction.

II): In comparing the metachromasia obtained with toluidine blue and methyl violet, it was noted that on incubation with the periodic acid Schiff-positive amyloid fraction, amyloid metachromosia after methyl violet staining was inhibited less than after toluidine blue staining.

III): It is emphasized that a competition between dye and proteins occurs in metachromatic staining reactions.

IV): Inhibition of amyloid metachromasia in histological tissue sections could not be demonstrated with the techniques used.

Studies of the composition of secondary amyloid

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