ABSTRACT
The current concept of biological membranes is a dynamic molecular assembly characterized by the coexistence of structures with highly restricted mobility and components having great rotational freedom. Microviscosity should be regarded as an operational term which was introduced for the application of classical hydrodynamic expressions to microscopic fluid regions, like the lipid bilayer of biological membranes. The first quantitative method for the determination of membrane fluidity in live cells on a single cell level was developed by M. Inbar. In addition, the effect of photobleaching is much less in flow cytometry than in spectrofluorimetry, since the cells reside in the laser beam only for microseconds. Application of the latest developments in experimental techniques for generating new data and their detailed and thorough analysis may result in better understanding of the correlation between membrane structure and dynamics and the metastasis. Cell differentiation and maturation entail a series of membrane events, which are modulated by the dynamic structure of the plasma membrane.
