Improvements and important considerations of an ex vivo assay to study Candida albicans-splenic tissue interactions.

Improvements were made on an ex vivo assay to study adherence properties of Candida albicans to host internal organs. The assay is applicable to understanding mechanisms of C. albicans dissemination following a fungemia. Binding patterns of yeast forms to splenic tissue are intriguing and we found the following modifications to be especially relevant. Mice serving as spleen donors for the assay should be injected with 0.1 ml i.v. of a 10% concentration of luconyl blue, 5 min before killing. After collecting splenic sections on a glass slide, 100 microliters of a 1-2 x 10(8)/ml suspension of stationary yeast cells should be applied to the sections. The assay does not require a carbonate buffering system or serum supplements. Attachment of yeasts to host tissue occurs best if the interaction is allowed to proceed without agitation by rotation. Assessment of binding is facilitated by staining the slides with crystal violet and computer image analysis can be used for quantification of binding.