SPECTRAL-ANALYSIS OF ERYTHROCYTE FLICKERING IN THE 0.3-4-MU-M-1 REGIME BY MICROINTERFEROMETRY COMBINED WITH FAST IMAGE-PROCESSING

Reflection interference microscopy in combination with real-time image processing was applied to determine the spatial spectrum of the mean-square amplitude of erythrocyte flickering in the wave-vector regime 0.3 less-than-or-equal-to q less-than-or-equal-to 4 mum-1. The mean-square amplitude scales as q4+/-e for q greater-than-or-equal-to 0.7 mum-1, suggesting that flickering is dominated mainly by bending stiffness. We measured a bending modulus of K(c) = (2 +/- 0.5) x 10(-20) N m as compared to K(c) = (5 +/- 1.5) x 10(-20) N m found for dimyristoylphosphatidylcholine (DMPC) vesicles with the same technique.