Figure 4

Orthogonal Partial least squares discriminant analysis (OPLS-DA) score plot showing a clear separation of the different saliva collection methods.

The separations are based on the proteins tabulated in Table 3. The protein patterns of unstimulated sublingual saliva (red squares) and unstimulated whole saliva (orange triangles) are clustering together. Stimulated parotid saliva (green triangles) and unstimulated parotid saliva (green stars) are clustering together. The protein patterns of stimulated whole saliva (yellow squares) and stimulated sublingual saliva (purple circles) differs clearly from the other collection methods. Estimate of prediction Q2 = 0.79 and R2 = 0.93. The ellipse shows the 95% confidence interval using Hotelling T² statistics.