FIG. 9.

Microbial inhibition analysis for antibiotics. (a) Schematic of a model inhibition assay. In droplets containing an antibiotic (green labeled) bacterial growth is inhibited, whereas in droplets without antibiotic (unlabeled, gray) bacterial cells proliferate. Empty droplets (far-red labeled) are used as control droplets. (b) The three populations were classified into three clusters by simultaneously measuring absorbance, scattered, and fluorescence signals. Droplets with antibiotic and inhibited cell growth had low red fluorescence and scattered light signal (green cluster). Droplets without antibiotics and cell growth had high absorbance and red fluorescence signal (black cluster). Small gray dots represent 2D scatter plots of measured signals. Lower images are microscopic images of droplets in brightfield, darkfield, red, green, and overlay of fluorescence channels. Far-red fluorescence is not visible in microscopic images.