Measurement of intracellular iodophilic polysaccharide in two cariogenic strains of Streptococcus mutans by cytochemical and chemical methods.

Quantitative cytological and chemical methods have been developed to study the intracellular iodophilic polysaccharide (IPS) content of two strains of Streptococcus mutans. The cytological method uses a periodic acid-chlorite treatment of thin sections to increase the affinity of IPS for uranyl and lead salts. This results in the IPS appearing as individual electron-dense granules which can be counted for quantitative studies. As a basis for these quantitative studies, IPS was measured chemically by dissolving whole cells with hot KOH and quantitating spectrophotometrically the amount of iodine-polysaccharide complex formed.