A convenient and reproducible filtration technique for the determination of erythrocyte deformability

A simple method for the determination of red cell filterability (deformability) in leucocyte-free suspensions of washed erythrocytes is described. All equipment used is inexpensive and readily available. Polycarbonate membranes of 5 microns porosity are regenerated after each filtration. Consecutive filtration measurements allow for very good precision. The proposed method has high sensitivity for suspensions of overall slightly stiffened red cells or mixtures of normal and small numbers of greatly abnormal erythrocytes. In the latter case the method also fractionates. The method has been tested in vitro. Both human albumin solution and acetyl salicylic acid increased erythrocyte filterability. Chlorhexidine and silver sulphadiazine on the other hand adversely affected filterability. The technique is very suitable for the investigation of the effect of pharmacologically active materials on red cell filterability (deformability).