FIG 1.

Quantifying live microbial load and composition in human saliva. (A) Schematic illustrating how PMA removes DNA not protected by an intact cell membrane. (B) Flow cytometric quantification of microbial load matches CFU estimation more closely when the sample is pretreated with PMA for both a Gram-positive bacterium, E. coli, and a Gram-negative bacterium, S. aureus. Each point represents technical triplicates of each method, with the standard deviation shown for the CFU measurement (x axis) and flow cytometry measurement (y axis). (C) Schematic of sample collection and processing allowing for measurement of unstimulated salivary flow rate, live and total microbial load, and live and total microbial composition.