FIGURE 4.

Typical rotation spectra of Jurkat cells in sorbitol- (A) and trehalose-substituted media (B) of different osmolalities, but of the same conductivity of 140 μS/cm. ROT spectra were measured after 15–30 min incubation in 300- and 100-mOsm solutions (solid and open symbols, respectively). For each sugar, ROT spectra of 9–13 cells were measured at each osmolality. Continuous curves are best fits of the single-shell model. The fitted parameters are given in Table 1. The characteristic frequencies (f_c1 and f_c2) with corresponding rotation amplitudes (R₁ and R₂) are defined in the text (Electrorotation theory).