This Small Business Innovation Research (SBIR) Phase I project proposes to develop a flow cytometer for sorting cells based on chemical phenotyping, which (1) provides quantitative analysis of specific molecular species, (2) has single cell sensitivity, (3) is high throughput, (4) label-free, and (5) non-destructive to living organisms. The proposed system uses coherent Raman scattering (CRS), a laser spectroscopy based on analysis of the vibrations of chemical bonds. Compared to conventional Raman scattering, the CRS signal is coherently amplified, which should achieve sorting speeds up to 10,000 cells/s, which is >10,000x faster than what can currently be achieved with spontaneous Raman. Reaching this goal requires development of (1) a spectrally multiplexed CRS system based on a narrowband pump laser and a broadband probe laser, and (2) a high-speed, high-sensitivity multichannel detection system to simultaneously probe multiple spectral components of the broadband pump laser. The broader impact/commercial potential of this project derives from the variety of potential applications of this novel phenotyping technology in basic and applied R&D. One example is in the field of products from biological organisms (e.g., algae or yeast) including fuels and specialty chemicals, where the organism synthesizes the target chemical using energy either harvested from sunlight or from a low-value feedstock, such as glucose. Genetic modification is used to improve yield and specificity for the target chemical species. The process of mutation and selection can be repeated until an optimized outcome is obtained. High-throughput chemical phenotyping is required to sample a large number of genetic mutations and speed up the directed evolution process. It would be advantageous to perform such biochemical analysis non-destructively, so that the fitness of candidates could be tested in growth and stress assays after selection. In addition to biofuel production, there are numerous applications in basic research, as well as medical applications in both diagnostics and treatment
