On-target digestion of collected bacteria for MALDI mass spectrometry
An on-target protein digestion system was developed for the identification of microorganisms in collected bioaerosols using off-line matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Bacteria analysis techniques based on MALDI-MS were adapted for use with an orthogonal MALDI quadrupole-time-of-flight mass spectrometer. Bioaerosols were generated using a pneumatic nebulizer and infused into a chamber for sampling. An Andersen N6 single-stage impactor was used to collect the bioaerosols on a MALDI target. On-target digestion was carried out inside temporary mini-wells placed over the impacted samples. The wells served as miniature reactors for proteolysis. Collected test aerosol particles containing the protein cytochrome c and E. coli bacteria were proteolyzed in situ using trypsin or cyanogen bromide. A total of 19 unique proteins were identified for E. coli. Using the TOF-MS spectra of the digested samples, peptide mass mapping was performed using the MASCOT search engine and an iterative search technique. © 2008 Elsevier B.V. All rights reserved.
Publication Source (Journal or Book title)
Analytica Chimica Acta
Dugas, A., & Murray, K. (2008). On-target digestion of collected bacteria for MALDI mass spectrometry. Analytica Chimica Acta, 627 (1), 154-161. https://doi.org/10.1016/j.aca.2008.07.028