Lateral Filter Array Microfluidics for Circulating Tumor Cell Isolation

Research focus

Circulating tumor cells are shed into the bloodstream by solid tumors, and capturing them from a routine blood draw offers a route to cancer diagnosis and monitoring that does not require a biopsy. The difficulty is abundance: the target cells are vanishingly rare against a background of red and white blood cells, so any capture method has to be both highly selective and gentle enough that the cells survive to be analysed.

The lateral filter array microfluidic device addresses this with geometry. A serpentine main channel carries the bulk of the sample while an array of side filters, sized between the diameters of a blood cell and a tumor cell, traps the larger cells off the main flow path. Because the filters sit lateral to the flow rather than across it, the device resists the clogging that limits conventional membrane filtration. My work concerns the relationship between that geometry and how well it actually captures, and pairs the physical separation with the chemistry that has to happen downstream.

My responsibilities

I built a COMSOL model of the microfilter array relating channel size and volumetric flow rate to capture efficiency, so that a device could be designed toward a target rather than found by iteration. I then fabricated and tested more than 200 microfluidic devices to validate that model, working through mask design, soft lithography, and fluorescence microscopy for readout, and cross-checking predicted against measured capture using clinical samples supplied by UF Health Shands Hospital.