Affiliations: [a] Department of Haematology, Medical School, University of Birmingham, Birmingham B15 2TJ, UK | [b] Department of Medicine, Inselspital, University of Bern, Bern, Switzerland
Correspondence:
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Correspondence to: Dr. M Stäubli, Department of Medicine, Inselspital, 3010 Bern, Switzerland.
Note: [] Accepted by: Editor M.R. Boisseau
Abstract: A new instrument (Radial Spreading Rheometer) has been deve loped to measure the radial spreading time of a concentrated washed erythrocyte suspension through a horizontally suspended filter paper. A calibration time (CT) for radial spreading of buffer was used to calibrate individual filter papers. The radial spreading time (RST) for washed erythrocytes was then expressed as the ratio RST/CT and adjusted to a standard packed cell volume of 0.50 (50%). The ratio RST/CT was independent of (a) temperature within the range 20–35°C, (b) leucocyte count up to 5.0 × 109/l, and (c) platelet count up to 76 × 109/l. The ratio RST/CT correlated significantly (r = 0.418, P < 0.05) with erythrocyte mean cell haemoglobin concentration but not with mean cell volume. Radial spreading rheometry is a low-cost technique for measuring erythrocyte deformability by bulk flow of a concentrated cell suspension through the wide channels of paper filters.
