title: Microsecond Scale Vibrational Spectroscopic Imaging by Multiplex Stimulated Raman Scattering Microscopy.
abstract: Real-time vibrational spectroscopic imaging is desired for monitoring cellular states and cellular processes in a label-free manner. Raman spectroscopic imaging of highly dynamic systems is inhibited by relatively slow spectral acquisition on millisecond to second scale. Here, we report microsecond scale vibrational spectroscopic imaging by lock-in free parallel detection of spectrally dispersed stimulated Raman scattering signal. Using a homebuilt tuned amplifier array, our method enables Raman spectral acquisition, within the window defined by the broadband pulse, at the speed of 32 microseconds and with close to shot-noise limited detection sensitivity. Incorporated with multivariate curve resolution analysis, our platform allows compositional mapping of lipid droplets in single live cells, observation of intracellular retinoid metabolism, discrimination of fat droplets from protein-rich organelles inCaenorhabditis elegans,spectral detection of fast flowing tumor cells, and monitoring drug diffusion through skin tissuein vivo. The reported technique opens new opportunities for compositional analysis of cellular compartment in a microscope setting and high-throughput spectral profiling of single cells in a flow cytometer setting.
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Chien-Sheng
authors.initials: CS
authors.lastname: Liao
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Mikhail N
authors.initials: MN
authors.lastname: Slipchenko
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Junjie
authors.initials: J
authors.lastname: Li
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Seung-Young
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Oglesbee
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA ; Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Ji-Xin
authors.initials: JX
authors.lastname: Cheng
keywords: Optical microscopy; Raman scattering; Vibrational spectroscopy