Saliva Collection for Raman Analysis

In this study, five volunteers with good health status, and with no previous diagnosis of cardiovascular diseases, neurological or severe systemic disorders, were enrolled (average age 33.4 y/o; all subjects were female and non-smokers). According to the Helsinki Declaration, ethical approval was obtained from the Institution Ethical Committee and all recruited subjects signed informed consent forms before the collection of serum and saliva samples. Serum was obtained by the centrifugation of blood at 2500 g for 10 min at room temperature, and then stored at −80 °C before analysis. For the collection of saliva, Salivette^® swabs were purchased from Sarstedt (Sarstedt AG & CO, Numbrecht, Germany). Each Salivette^® contains a cotton swab that can filter saliva and retain any food residues. The saliva collection procedure was performed following the manufacturer’s instructions. Briefly, the swab was placed in the mouth and chewed for one minute, at least two hours after the last meal and teeth brushing. Then, the swab was centrifuged at 1000× g for 5 min in order to recover the biofluid. Saliva samples were stored at −20 °C before analysis. This method was previously reported for the collection of saliva for Raman analysis, demonstrating no interference in the subsequent spectroscopic evaluation [6 (link),7 (link),8 (link),9 (link)].