Continuous high throughput molecular adhesion based cell sorting using ridged microchannels.

Cell molecular interactions govern important physiological processes such as stem cell homing, inflammation and cancer metastasis. But due to a lack of effective separation technologies selective to these interactions it is challenging to specifically sort cells. Other label free separation techniques based on size ,stiffness and shape do not provide enough specificity to cell type, and correlation to clinical condition .We propose a novel microfluidic device capable of high throughput molecule dependent separation of cells by flowing them through a microchannel decorated with molecule specific coated ridges. The unique aspect of this sorting design is the use of optimized gap size which is small enough to lightly squeeze the cells while flowing under the ridged part of the channel to increase the surface area for interaction between the ligand on cell surface and coated receptor molecule but large enough so that biomechanical markers, stiffness and viscoelasticity, do not dominate the cell separation mechanism. We are able to separate Jurkat cells based on its expression of PSGL-1ligand using ridged channel coated with P selectin at a flow rate of 0.045ml/min and achieve 2-fold and 5-fold enrichment of PSGL-1 positive and negative Jurkat cells respectively.