High Speed Raman Cytometry
LLNL: J Chan, UCD: Doug Taylor, Thomas Huser, UCB: L Lee, A Lau
The goal of this project is to develop Raman cytometry as a new clinical diagnostic tool to complement existing fluorescence based cell sorters. We are working on developing different optical and microfluidic platforms that, when combined with our laser tweezers Raman spectroscopy efforts, will enable Raman flow cytometry, in an integrated optofluidic Raman activated cell sorter (RACS) for the automated delivery, manipulation, analysis, and sorting of single cells from a continuous flow of cell samples. The system would provide several advantages over existing fluorescence-based cell sorters (FACS): it does not rely on the use of fluorescent labels, provides unique intrinsic biochemical information of a cell, and is nondestructive and noninvasive.
Over the past year, we have begun to design and test different multichannel microfluidic devices that would be most appropriate for our proposed RACS system. The principle of operation involves trapping individual cells flowing within an inlet channel and manipulating them into adjacent channels for Raman analysis and sorting. Microfluidic devices based on hydrodynamic focusing and pinch flow fractionation have been evaluated for their suitability for LTRS based on the effect of their flow velocity on the laser trapping properties. In addition, we have begun to assess the use of coherent anti-Stokes Raman scattering (CARS) spectroscopy for single cell interrogation as a means to achieve sorting with higher throughput.