MEMS Seminar: Single Cell Enzyme Analysis for Precision Medicine by Using Continuous Flow Microfluidics
Monday, October 16, 2017 - 10:00am to 11:00am
Chia-Hung Chen, Ph.D.
In the context of tumor biopsy analysis, the implementation of personalized medicine requires clinical measurements which consider not only patient genetic information, but also tumor cell heterogeneity, single cancer cell phenotype and its functionalities to determine disease progression. To address this challenge, several platforms were developed before, while the contradiction between high throughput single cell screening and comprehensive cell functional analysis remained. In this study, a novel high throughput screening system integrating multiple fluorescence detectors and a computational method was developed as a functional flow cytometer (Droplet-FACS) to screen multiple proteolytic activities of whole patients’ tumors at single cell resolution with continuous flow manner. To perform single cell multiplexed functional assay, firstly, individual cells were dissociated from a tumor and were encapsulated into water-in-oil droplets containing four FRET-substrates, which gave distinct fluorescent readout for multiplexed protease assay. The excitation and emission filters were integrated in an automatic optical system to obtain real time multiple fluorescent signals without crosstalk. These fluorescent signals were detected by four photomultiplier tubes, where voltages were converted to digital signals for rapid computational analysis through Proteolytic Activity Matrix Analysis (PrAMA). Accordingly, six MMPs/ADAMs activities were estimated to infer cell migration capability. With this microfluidic system, more than 2x105 single cell’s multiple protease activities were determined with a throughput of ~10 cells per second, rapidly characterizing a comprehensive cell population distribution of a primary tumor, based on protease enzyme activities to precisely indicate clinical situations.