Light scattering of human red blood cells during metabolic remodeling of the membrane

Abstract

We present the light scattering properties of individual human red blood cells (RBCs). We show that both the RBC static and dynamic scattering signals are altered by adenosine 5'-triphosphate (ATP)-driven membrane metabolic remodeling. To measure the light scattering signal from individual RBCs, we use diffraction phase microscopy together with a Fourier transform light scattering technique. RBC cytosolic ATPs are both chemically and metabolically depleted, and the corresponding scattering signals are compared with the light scattering signal of normal RBCs having physiologic levels of ATP.

Figure 1

The static scattering signal of RBC and the effects of ATP. Topographies of RBCs measured by diffraction phase microscopy: (a) a healthy RBC, (b) a RBC with irreversibly depleted ATP (low dose of inosine and iodoacetamide), and (c) high dose of inosine and iodoacetamide. Units for colorbar are micrometers. Scale bar indicates 5 μm. Light-intensity scattering patterns of (d) healthy RBCs, (e) RBCs with irreversibly depleted ATP (low dose of inosine and iodoacetamide), and (f) high dose of inosine and iodoacetamide. The thick line indicates the mean value and the area indicates the standard deviation (N = 30∕group). (g) p-values of scattering patterns between healthy RBCs and different groups of RBCs. (Color online only.)

Figure 2

Dynamic light scattering of RBCs with different cytosolic ATPs. Normalized temporal autocorrelations as a function of decay time and scattering angle of (a) healthy RBCs, (b) RBCs with irreversibly depleted ATP (low dose of inosine and iodoacetamide), and (c) high dose of inosine and iodoacetamide (N = 30∕group).

Figure 3

(a) Line width Γ and (b) peak frequency ω₀ extracted from intact RBCs and RBCs with irreversibly depleted ATP (low and high doses of inosine and iodoacetamide). Error bars indicate the standard errors (N = 30∕group).

Figure 4

(a) Line width Γ and (b) peak frequency ω₀ extracted from intact RBCs, RBCs with metabolically depleted ATP, RBCs with ATP was reintroduced (+ATP), and ATP-reintroduced RBCs measured after 6 and 24 after adding ATP. Error bars indicate the standard errors (N = 30∕group).