Effects of irradiation or filtration of whole saliva on the concentration of proteins (A and B) and integrity of fluorophores (C and D), as well as enzymatic activities of amylase (E and F) or lysozyme (G and H). Salivary samples were irradiated (A, C, E, and G) with doses up to 10 kGy or filtrated (B, D, F, and H) with membrane filters of decreasing pore size. Irradiation was performed in three independent experiments on samples from three individuals (•, ▴, and ▪). Each data point represents the result from one donor in one experiment. Filtration was performed in five (B) or two (D, F, and H) independent experiments on samples from two individuals (• and ▴). The dashed horizontal line shows the 50% margin.