Microfluidic Cell Sorting and Bacterial Detection with Polymeric Film Imprinting

Researchers in Prof. Dick Zare's laboratory have developed an efficient, label-free platform to separate and detect cells, bacteria, or other particles in fluid samples. This method employs cell/particle cavities created in a polymeric film (imprinted polymeric film, IPF). When incorporated into microfluidic chips, the IPFs chemically recognize particles or cells of interest in a sample and selectively re-adsorb them within minutes. Unlike FACS (fluorescence-activated cell sorting), the IPF-based technology can sort multiple cells simultaneously and does not require fluorescent labels. This method is well-suited for recognizing bacterial cells or other particles that are too large for chromatography. This technique could be applied to cell sorting from any fluid sample (such as water, blood, urine or plasma) for research or diagnostics.

Schematic (left) and confocal microscopy image (right) of cell imprints on a polymer surface. The IPF is generated by pressing bacteria adhered on a glass plate into a prepolymer. After the polymer is cured and the glass plate removed. The remaining cavities resemble the cells in size and shape. (Remaining cells can be completely removed by sonication.)

Stage of Research
The inventors have demonstrated this technology using IPF templates in a microfluidic chip to separate strains of cyanobacteria with 80-90% efficiency. The inventors continue to research the platform as a diagnostic tool for tuberculosis and are developing modifications to improve safety and optimize detection.