Affinity adsorption of Saccharomyces cerevisiae on concanavalin A perflurocarbon emulsions

Perfluorocarbon affinity emulsions have been generated by immobilizing concanavalin A onto the surface of triazine-activated perfluorocarbon droplets. Immobilized concanavalin A densities of 0.1, 0.7 and 2.1 mg/ml were obtained by varying the concentration of cyanuric chloride used for activation. The affinity emulsions were found to adsorb Saccharomyces cerevisiae cells from solution with adsorption capacities of 1 x 10(9) cells, 4.6 x 10(9) and 6 x 10(9) cell/ml, respectively. Optimal conditions for the elution of bound cells were obtained by studying inhibition curves of concanavalin A-mannan precipitation using simple sugars. Methyl alpha-D-mannopyranoside showed the greatest inhibitory power with 50 per cent inhibition displayed at a concentration of 0.05 mM. Experiments carried out examining the concentrations of methyl alpha-D-mannopyranoside necessary to dissociate a concanavalin A-mannan precipitate demonstrated that at least a seven-fold higher concentration of methyl alpha-D-mannopyranoside was required for dissociation than that required for inhibition of its formation. The efficiency of elution of bound yeast cells was found to be dependent on the concentration of methyl alpha-D-mannopyranoside used, the time of elution and the immobilized ligand density. Thus, 100 per cent elution was obtained with a concanavalin A affinity emulsion (0.1 mg/ml) by incubation with 500 mM methyl alpha-D-mannopyranoside for 1 h.