The entire blood samples used in this study have been obtained from Swat region, the northern part of Pakistan. These samples have been confirmed for dengue virus infection on the basis of serological tests. In addition, 25 samples have been collected from healthy volunteers of the same region to make a comparison with the diseased one. The blood samples of about 3 ml have been collected from each individual with the help of a sterile syringe. All the samples (healthy and infected) have been centrifuged at 3500 rpm for 10 min using Hittich Centrifuge D-7200. The obtained sera have been aliquoted in different tubes and stored at −80 °C till use. For obtaining the Raman spectra a quantity of about 15 μl of each sample has been placed on the glass slide and dried for about 2 h at room temperature.