Technology Notes #2

Technology Notes - Whole Cell Analysis by Mass Spectrometry

By Robert B. Harris, Ph.D.
President and CEO

In another application of mass spectrometry, CBI scientists have implemented methods by which a "molecular mass spec fingerprint" is prepared from viable whole cells, and in particular, from select agent pathogens.

These molecular signatures represent diverse classes of mass species which are ablated from the surface and perisplasmic space of the target bacteria in the beam of the impinging laser. The ablated mass species are then detected in the mass spectrometer and a visual signature of the different mass species is collected into a fingerprint.

Much like human fingerprints, these mass spec fingerprints are absolutely characteristic of the organism from which it was derived. That is, the mass spec fingerprint of E. coli, for instance, is very different than the mass spec fingerprint of Y. pestis and the mass spec fingerprint of S. aureus is very different from that of B. anthracis, and so forth. All of the mass spec fingerprints prepared from the different strains and species of bacteria are collected into a "Master Fingerprint Library" so that when a spectrum is obtained from an unknown bacterial sample, query of the Master Fingerprint Library with the unknown spectrum returns a degree of correlation for the best fit. The higher the degree of correlation, the more positive the assignment of the unknown.

CBI is using this technique to rapidly detect and confirm particular bacteria in pure cultures and in complex mixtures of different bacteria.

Commonwealth Biotechnologies, Inc. 601 Biotech Drive, Richmond, VA 23235 800-735-9224 (800-RELY-CBI) FAX: 804-648-2641 email: info@cbi-biotech.com