Streaming Potential Measurements of Biosurfaces

A technique based on the measurement of streaming potentials has been developed to evaluate the electrokinetic region of the cell periphery. This approach is feasible for cell lines propagated in in vitro cell culture in mono-layer form. The advantage of this system is that cells may be evaluated in the l iving state attached to a substrate. Thus it is not necessary to subject the cells to enzymatic, chemical, or mechanical t rauma required to obtain monodisperse suspensions which are then normal ly evaluated by microelec-trophoresis. In this manner it should be possible to study the influence of substrate and environmental factors on the charge density and potential at the cell periphery. The apparatus and procedure are described as well as some results concerning the electrokinetic (f) potential of borosil icate capil-laries as a function of ionic strength, pH, and temperature. The effect that turbulence and entrance flow conditions have on accurate streaming potential measurements i discussed. The f-potential of BALB/c 3T12 fibroblasts ha