Quantitative agar-invasion assay.

A new method for quantification of yeast invasion into the agar medium was developed. Classical agar-invasion assays have been the methods of choice for determination of yeast invasion, but their main disadvantage is the lack of quantification. Our new Quantitative yeast agar-invasion test allows for quantitative measurements and enables sorting strains by their degree of invasiveness. The invasion abilities were measured for 10 clinical and non-clinical Saccharomyces cerevisiae strains and a strain of Candida albicans. Finally, the correlation between the degrees of strains invasiveness and their reported virulence was observed, proposing our assay as a method for quick determination of yeast virulence potential.