Raman-based diagnostic tools to distinguish anemias and to evaluate the expression ratio of S and C hemoglobins

Cellular imaging techniques based on vibrational spectroscopy (Raman) are powerful tools in cell biology because the molecular composition of sub-cellular compartments can be visualized without the need for labeling [1]. Moreover resonance Raman (RR) spectroscopy is an ideal method to elucidate the structural characteristics of heme domains in hemoproteins, directly monitoring the iron-axial ligand bond strength. The information provided is important in understanding the mechanisms of protein control of heme reactivity [2]. In this context, Optical Tweezers (OT) have revealed a formidable tool to select and manipulate single particles, included cells or cellular organelles, allowing a rapid identification of the changes, at single cell level, in response to external agents, environmental stress, or in presence of cellular disorders [3]. Haemoglobinopathies are inherited disorders defined as qualitative or quantitative deficiency of haemoglobin (Hb) in red blood cells (RBCs). Herein we analyze anemic RBCs with two human Hb variants, HbS and HbC (Gluβ6Val and GlubβLys, respectively). A comparative study in a family (mother, father and daughter, respectively heterozygous for HbS, HbC and Hb C+S) shows that different Raman images and mechanical properties of healthy and anemic RBCs could help to evaluate the expression ratios between HbS and HbC, and correlate these data with varied clinical conditions. References [1]. van Manen H.J., et al., Proc. Natl. Acad. Sci. 2005, 102, 10159. [2]. Vitagliano L., et al., J. Am. Chem. Soc. 2008, 130, 10527. [3]. De Luca A.C., et al., Opt. Exp. 2008, 16, 7943. AV and LM acknowledge PRIN 2007 funds.