Abstract
The cell is a system in which large number of various functions are integrated into the micrometer scale.And theformation of the phase–separated micro domains plays an important role for this integration to make heterogeneousregions in a small area. Indeed, phase-separated micro domain, ‘raft’was found in plasma membrane of a cell.Important biological functions such as GPI–anchored protein and virus receptor are located in the raft. In order toinvestigate phase–separated micro domains, the authors have developed microscopic imaging instrument using envi-ronment sensitive fluorescence dye, laurdan. The instrument was applied to a model of raft, which elucidatedenzymic conversion of sphingomyelin to ceramide destroyed phase–separated micro domains.
