- Oral fluid samples from experiment 2 served as the negative oral fluid control (D0, prior to inoculation) and positive oral fluid control (D15, post-inoculation) for calculating sample-to-positive (S/P) ratios for experiment 1 (orange highlight). Oral fluid samples from experiment 1 served as the negative oral fluid control (D0, prior to inoculation) and positive oral fluid control (D55, post-inoculation) for calculating S/P ratios for experiment 2 (gray highlight). S/P ratios for the oral fluid samples highlighted in yellow were calculated using the kit-supplied negative control (− control) and positive control (+ control). S/P ratios were calculated using optical density (OD) measurements in the following formula:
- S/P = (ODsample – ODNC)/(ODPC – ODNC)
- Ratios ≥0.25 were considered positive while < 0.25 were considered negative
