Alexandra Weinhofer

Alexandra Weinhofer – UMass Trainee 2023-2025

I am a PhD student in the Santore lab. I am studying bacterial capture on polymeric substrates under flow conditions specifically to decouple the physico-chemical and mechanical interactions. Bacteria is tracked in a flow chamber to monitor its capture on a coverslip, which is treated to have hydrophilic, hydrophobic, or cationic functionality. Also, regarding the surface treatments on the coverslips, I have altered the stiffness of the polyethylene glycol (PEG) hydrogels and synthesized a poly-L-lysine-PEG grafted copolymer for future use in capturing bacteria. I developed a video analysis program in Python to automate the tracking and counting of particles.

I began my trial experiments with the flow chamber with 1 µm silica particles to assure that my videos for particle tracking were in focus. After flowing in FITC-dextran, I was able to observe the contact area of the particles under total internal reflection fluorescence (TIRF) microscopy. Simultaneously, in January 2024, I began to culture flagella-free E. coli. I have started experimenting with flowing E. coli cells through the flow chamber to check for bacterial capture on acid-etched coverslips.