Affiliations: Department of Physiology, Technical University of Aachen, Medical School Pauwelsstraße 30, D-52074-Aachen, Germany | Division of Neonatology, Department of Pediatrics, University of Heidelberg, Medical School, Im Neuenheimer Feld 150, D-69120 Heidelberg, Germany
Abstract: The Rheodyn SSD is an automated laser diffractometer for rapid measurement of red blood cell (RBC) deformability in small quantities of blood. RBC are suspended in a viscous medium and placed between a rotating and a stationary disk. Defined shear stresses of 0.3 to 60 Pa force the RBC to deform to ellipsoids, causing elliptical diffraction pattern of a laser beam passing through the RBC suspension. At shear stresses of 3 to 60 Pa, coefficient of variation was <3% for repeated measurements of the same blood sample. RBC deformation was not affected by the anticoagulant (no anticoagulant, heparin, EDTA, or citrate), the sample size (10 to 50 μl of blood) and washing of RBC. The results show that the Rheodyn SSD is a reproducible tool to study RBC deformability in small blood samples.
