Fig. 4.

Schematic representation of the microfluidic agarose channel (MAC) system for antibiotic susceptibility testing: (a) Polydimethylsiloxane (PDMS) fabricated MAC chip is assembled with PDMS-coated glass. Central channel of the chip is loaded with an agarose-bacteria mixture and varying concentrations of antibiotic are added from the side-branched channels. To analyze bacterial growth, each interface between the agarose-bacteria and antibiotic in solutions was monitored using a microscope. (b) Zoom in view of MAC chip (i) The empty channels. (ii) Main channel loaded with the agarose-bacteria mixture (iii) Antibiotic diffusion channels showing a sharp interface generated between the side-branched channels and the main channel. (iv) Microscopic monitoring of bacterial cell growth over time. [Created with BioRender.com.]