Citation: Analytic Chemistry, ASAP Article 10.1021/ac070681h S0003-2700(07)00681-6
Web Release Date: June 9, 2007

RSI Scientists Charles K. Manka and Sergei Nikitin are prominent contributors to an NRL research group that first demonstrated  using two-dimensional resonant-Raman spectra to identify  bacteria, including differentiation of genetically similar species.  Developed specificaaly for this purpose, the new device sequentially illuminates bacteria with 200 different ultraviolet wavelengths and measures the spectrum at each.  Information in the two-dimensional spectra should allow identification of bacteria and chemicals in environments containing multiple organisms and chemicals.   This invention, designated swept wavelength optical resonant-Raman device (SWOrRD), may lead to instruments that rapidly identify bacteria in hospital and food plant settings, for screening large populations, and for biochemical-threat warning systems.

Bacterial signatures. Two-dimensional resonant-Raman signatures of E. coli (top row), Y. rohdei and S. epidermidis (middle row), with B. cereus and B. thuringiensis (bottom row). The horizontal axis in each frame is the Raman shift, from 900 to 1800 cm-1, relative to the excitation laser wavelength. The vertical axis is the laser wavelength from 210 to 270 nm. Colors represent the relative amplitude of resonant-Raman scattering from the bacteria.

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