Giles, Charles H. (The University of Strathclyde, Glasgow, Scotland), and Robert B. McKay. Adsorption of cationic (basic) dyes by fixed yeast cells. J. Bacteriol. 89:390-397. 1965.-The adsorption of 10 typical cationic dyes on formalin-fixed yeast cells has been studied by determining isotherms, and the results are consistent with an ion-exchange mechanism. The adsorption on this complex substrate is similar to that on the simpler substrate, alumina. The dyes are probably aggregated when adsorbed, and the size of the aggregates increases with increase in the molecular weight of the dye ion. After considering the possible adsorption sites, and comparing the data with adsorption on simpler substrates, we suggest that the most important adsorption sites may be phosphate or other strongly acidic groups.