Compartmentalized Single Cell Analysis – Antibiotic Susceptibility and Protein Screening

Andersson Svahn, Helene

Droplet microfluidics is a technological platform that utilizes monodisperse aqueous droplets in a continuous biocompatible oil phase as controllable picoliter microreactors. We have developed several droplet microfluidic assays such as a method for detection and analysis of cell surface biomarkers on individual human cells using enzymatic amplification, high throughput sorting of droplets by size using deterministic lateral displacement and assays for automatic tracking and characterization of single cell behavior. Another research focus is droplet-based assays for directed-evolution of industrially relevant enzymes. We have also developed a miniaturized microwell slide for cell assays. The bottom of the wells is made out of a thin glass slide, which supports high-resolution imaging in contrast to the droplet microfluidic platform. We have developed a rapid and multiplex antibiotic susceptibility testing (AST) device using a functionalized microwell slide. The AST device has shown an accurate determination of the antibiotic susceptibility profile of bacteria at concentrations of 5-500 cfu/well. We combined real-time absorbance measurements of bacterial growth and a mathematical algorithm to determine the correct antibiotic treatment within 3-5 hours. The massive amount of acquired data was presented as a heat map, facilitating readout of the AST results. We believe that the AST device can provide a rapid and accurate way to determine bacterial susceptibility in the clinics.