DEFORMATION AND FLOW OF RED-BLOOD-CELLS IN A SYNTHETIC LATTICE - EVIDENCE FOR AN ACTIVE CYTOSKELETON

We introduce the use of microfabrication techniques to construct on a silicon wafer a synthetic capillary bed with 2.5- to 4-micron (mu)-wid e channels. Establishment of a fluid pressure gradient allowed us to o bserve simultaneously using optical microscopy hundreds of cells flowi ng through the bed at physiological speeds. We find a large distributi on of mobilities among red cells flowing through the structure; smalle r channels provide a greater impedance to flow than larger ones, indic ating that kinetic drag variations provide the origin of the distribut ion. The mobility of a particular cell is not correlated with the cell diameter but appears to be inversely correlated with intracellular ca lcium concentration of the cell, as determined by fluorescence of the calcium-binding dye fluo-3 AM. Also, we are able to use the parallel p rocessing nature of our arrays to observe isolated events where the ri gidity of the red cell seems to change suddenly over several orders of magnitude as it blocks a channel in the array.