THE INFLUENCE OF RED-CELL SIZE RELATIVE TO PORE-SIZE ON FILTRATION THROUGH NUCLEPORE FILTERS

A simple model relating pore passage time (PPT) to the degree of strai n of the membrane of a red cell of diameter D(C) on passing through a pore (diameter D(P)) has been developed. The model was tested for a ra nge of mammalian and fish species for which some data was available fo r more than one pore size. The strain (epsilon) is estimated as (D(C) - D(P))/D(C). For small epsilon, less than approximately 0.45, PPT was small but rose rapidly for higher values. The analysis provides a sim ple basis for choosing appropriate pore sizes, and consequently strain , for comparing mechanical properties of erythrocytes of different spe cies.