Here, we describe a simple microsphere-adhesion assay to characterize adhesive cues on living tissue slices, which we use to study pattern formation in neural tissue. This assay was developed by modifying a cell-adhesion assay on living tissue slices. We replaced dissociated cells by fluorescent microspheres and then coated the microspheres with isolated membranes from these cells. The membrane-coated microspheres were seeded on living tissue slices, and after a short incubation time, nonadherent microspheres were eliminated by washing. Then, the tissue slices with the adherent microspheres were analyzed using epifluorescence microscopy. As an example, it is shown that membrane-coated adherent microspheres were found to be distributed in a characteristic pattern on living slices of hippocampus, mimicking the adhesion pattern of dissociated living cells. The adhesion assay should be suitable to detect and to analyze adhesive cues on living slices of different tissues and, thus, might have numerous applications in tissue research and developmental studies. Here, we describe and discuss a detailed and improved protocol of the microsphere-adhesion assay.
