Most Recent Publications:
Pu Wang, Teng Ma, Mikhail N. Slipchenko, Shanshan Liang, Jie Hui, K. Kirk Shung, Sukesh Roy, Michael Sturek, Qifa Zhou*, Zhongping Chen* & Ji-Xin Cheng*, High-speed Intravascular Photoacoustic Imaging of Lipid-laden Atherosclerotic Plaque Enabled by a 2-kHz Barium Nitrite Raman Laser, Scientific Reports, 2014 November, 4: 6889. DOI:10.1038/srep06889 (2014)

Ping Wang, Bin Liu, Delong Zhang, Micah Y. Belew, Heidi A. Tissenbaum *, Ji-Xin Cheng*, Imaging lipid metabolism in live Caenorhabditis elegans using fingerprint vibrations, Angewandte Chemie Int Ed, 2014 October, 53: 11782-92.

Shuhua Yue, Junjie Li, Seung-Young Lee, Hyeon Jeong Lee, Tian Shao, Bing Song, Liang Cheng, Timothy A. Masterson, Xiaoqi Liu, Timothy L. Ratliff, Ji-Xin Cheng*, Cholesteryl ester accumulation induced by PTEN loss and PI3K/AKT activation underlies human prostate cancer aggressiveness. Cell Metabolism, 2014 March, 18: 393-406. PMID: 24606897, highlighted by Nature & Cancer Discovery.

Dec 2014: Cheng and coworkers received a 3-year, 1 million award frrom Keck Foundation to develop vibrational spectroscopic imaging tools for single cell analysis. Congratulations!

Dec 2014:  Hyeon Jeong Lee et al.'s work "Assessing Cholesterol Storage in Live Cells and C. elegans by Stimulated Raman Scattering Imaging of Phenyl-Diyne Cholesterol"  has been accepted by Scientific Reports (Nature Publishing Group) and is in press now. Congratulations!

Dec 2014: Chien-Sheng Liao et al.'s work "Microsecond Scale Vibrational Spectroscopic Imaging by Multiplex Stimulated Raman Scattering Microscopy" has been accepted by Light: Science & Applications (Nature Publication Group) and is in press now. Congratulations!

Dec 2014: Hyeon Jeong Lee received PULSe travel award! Congratulations!

Nov 2014: Pu Wang's work "High-speed Intravascular Photoacoustic Imaging of Lipid-laden Atherosclerotic Plaque Enabled by a 2-kHz Barium Nitrite Raman Laser" is highlighted on Biomedical Picture Of The Day (BPoD) website, which aims to engage everyone, young and old, in the wonders of Biomedicine. Please see more on BPoD webpage:, Facebook:, Twitter:, and Tumblr:

Nov 2014: Ji-Xin Cheng is named Chang-Jiang Professor by Chinese Ministor of Education.

Oct 2014: Ji-Xin Cheng is appointed to be Scientific Director of Label-free Imaging at Purdue's Discovery Park.

Aug 2014: Congratulations to Pu Wang, Delong Zhang, Steve Lee who received their PhD degrees.

March 2014: Ji-Xin Cheng becomes a Fellow of AIMBE (American Institute of Medicine and Biological Engineering)

Microsecond-scale Raman spectroscopic imaging for biology and medicine

In vivo Raman spectroscopic imaging is opening a new window of unveiling the cellular machinery by visualizing spatio-temporal dynamics of target molecules or intracellular organelles. However, challenges remain to be overcome. One is increasing spectral acquisition speed to microsecond scale for real time imaging and the other is extracting the spectrum from highly scattered photons. Single-color coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) have reached video rate imaging speed, albeit providing no spectral information and only applicable to mapping known species. Broadband CARS and multiplex SRS microscopy have pushed the spectral acquisition time to 3.5 ms and 32 μs, respectively. These methods used a spectrometer setting that is only suitable for non-scattering samples. For turbid biological systems in which nearly all photons are scattered, a paradigm-shifting scheme is to apply a large area detector to collect scattered photons and recover the spectrum thereafter. Here, we demonstrate vibrational spectroscopic imaging by multiplex-modulation and single photodiode detection of SRS signals. Compared to the spectrometer setting, our method improves the photon collection efficiency by 200 times for scattering systems and allows spectrum acquisition within 60 µs. In vivo imaging of vitamin E distribution on the mouse skin and in situ imaging of human breast cancerous tissues are demonstrated.