Biophysical Journal 86 4

Cover: Two-photon microscopy images of the distribution of laurdan generalized polarization in human red blood cells. The first column represents images of cells before treatment. In the second column, divalent cation has been added to the extracellular fluid. In the third column, an ionophore (ionomycin) has been added to introduce the ion into the cell. The top row depicts control cells, and samples in subsequent rows were treated with cobalt, magnesium, manganese, or nickel. False color indicates generalized polarization values with blue being the lowest (most fluid) and red the highest (most ordered). See article by Vest et al. on p. 2251.