A single 2 ml heparinised peripheral blood sample was centrifuges to get serum specimens. The Raman spectra (RS) of the solid residues from serum samples were measurement by placing 10µl of serum from the aliquots onto an aluminium substrate and allowed to dry for at least 30 min. The Raman system (Renishaw inVia Microscope integrated with Leica microscope) was calibrated with a silicon standard using the Raman peak at 520 cm-1. Multiple scans were conducted on the solid residue by moving the substrate on an X - Y stage. The wavelength of excitation was 785 nm and the laser beam was focused on the surface of the sample with a 50x objective. The radius on the beam was 3.0 µm and the laser power irradiation over the sample was 5mW. Each spectrum was taken with an exposure of 30s, 10 accumulation and collected in the region from 400 to 1540 cm-1.