Fig. 4.

The fluorescence spectra of pyrene. Temperature was varied in the order of 22, 4, 37, 22 °C after treating the cells with pyrene and fluorescence spectra of them were measured. When excimer of pyrene is formed in fluidic membrane, emission peak at 450 nm appears. As the peak at 450 nm disappeared at final 22 °C, local lipid domain seemed to form and allowed to become less fluidic at higher temperature than initial state