Microtest for mucopolysaccharides by means of toluidine blue: with special reference to hyaluronic acid.

LTHOUGH A VAST AMOUNT OF LITERATURE has been published in recent years on the subject of hyaluronic acid and hyaluronidase, owing to the importance of a biologic function which has been ascribed to these two substances, no satisfactory method yet exists for the determination of minute quantities of hyaluronic acid or other mucopolysaccharides. Various mucopolysaccharides form stable dispersions in water or buffer solutions. The stability of such suspensions can be destroyed by neutralizing the negative charges of the particles with charges of opposite sign.1 It has been possible in the present study to utilize the alkaline dye toluidine blue for this purpose. In the presence of the dye, hyaluronic acid and other mucopolysaccharides produce colored precipitates of characteristic morphology. Advantage has been taken of these properties to develop a microtest for the detection of minute quantities of hyaluronic acid and related mucopolysaccharides.