Raman spectroscopy has been applied to investigate the suitability of the drop coating deposition technique to study plasma samples from healthy donors and a patient with underlying cardiac condition. When blood plasma is deposited on a solid substrate, a droplet with coffee-ring is formed, and the plasma proteins will distribute inhomogeneously depending on the chemical and physical properties of the proteins. Changes in the fingerprint region of the Raman spectra were observed from the outer-ring and central zone of the droplet through a systematic investigation. For complete characterization of the sample, optimum measurement scheme has been proposed. To obtain clinically relevant information of the effects of immunoadsorption (IA) treatment of dilated cardiomyopathy (DCM) patient’s, Raman spectral information from outer-ring as well as from the central zone is required.