Raman Imaging Technique Identifies Pathogens

In the event of a biological attack, rapid methods for identifying pathogenic organisms will be important for mounting an effective response. Raman chemical imaging spectroscopy could be one of those methods.

Kathryn S. Kalasinsky of the Armed Forces Institute of Pathology, Patrick J. Treado of ChemImage, and coworkers report the development of a library of spectroscopic signatures for identifying bacteria in complex samples (Anal. Chem., DOI: 10.1021/ac0700575).

The researchers examined biothreat agents using optical and fluorescence imaging and then confirmed the identity of the organisms by their Raman spectral signatures. In one example, spores of Bacillus globigii, a close relative of Bacillus anthracis, were identified in a composite image by their different-colored fluorescence and Raman signals.

The method also is sensitive enough to detect single anthrax spores. In a blind study of 20 samples, the method correctly identified several pathogens, including B. anthracisand genetically similar bacteria.