Desorption electrospray ionization mass spectrometry of intact bacteria

Mohammed A. Meetani, Yong Seung Shin, Shaofeng Zhang, Richard Mayer, Franco Basile

Research output: Contribution to journalArticlepeer-review

74 Citations (Scopus)


Desorption electrospray ionization (DESI) mass spectrometry (MS) was used to differentiate seven bacteria species on the basis of their measured DESI-mass spectral profile. Both gram-positive and gram-negative bacteria were tested and included Escherichia coli, Staphyloccocus aureus, Enterococcus sp., Bordetella bronchiseptica, Bacillus thuringiensis, Bacillus subtilis and Salmonella typhimurium. Distinct DESI-mass spectra, in the mass range of 50-500 u, were obtained from whole bacteria in either positive or negative ion modes in less than 2 mins analysis time. Positive ion DESI-mass spectral fingerprints were compared using principal components analysis (PCA) to investigate reproducibility for the intraday and the day-to-day measurements and the method selectivity to differentiate the bacteria studied. Detailed study of variances in the assay revealed that a large contribution to the DESI-mass spectral fingerprint variation was the growth media preparation procedure. Specifically, experiments conducted with the growth media prepared using the same batch yielded highly reproducible DESI-mass spectra, both in intraday and in day-to-day analyses (i.e. one batch of growth media used over a 3-day period versus a new batch every day over the same 3-day period). Conclusions are drawn from our findings in terms of strategies for rapid biodetection with DESI-MS.

Original languageEnglish
Pages (from-to)1186-1193
Number of pages8
JournalJournal of Mass Spectrometry
Issue number9
Publication statusPublished - Sept 2007


  • Bacteria
  • Biodetection
  • Biomarkers
  • Desorption electrospray ionization
  • Principal components analysis

ASJC Scopus subject areas

  • Spectroscopy


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