Identification of saliva deterioration markers. A, RP-HPLC chromatograms of the < 5 kDa fraction of a mixed WS sample incubated for 0–8 h at 37°C. Samples were collected at t=0, 30 min, 2 h, 4 h and 8 h. Note that the intensity of most peptides increased up to 4 h, then decreased. The peptides indicated with arrows steadily increased over the entire time frame, and were collected. B, identification of the collected peptides. These peptides could potentially serve as saliva deterioration markers.