Bacteria secrete an incredible array of chemicals that affect their environment, neighboring microbes, and their hosts. But only a small number of these chemicals have been identified and characterized.
To improve detection of secreted microbial chemicals, Pieter Dorrestein of the University of California, San Diego, and colleagues employed a recently developed mass spectrometry (MS) technique called nanoDESI (nanospray desorption electrospray ionization), which enables the repeated sampling of living microbes right from petri dishes.
In nanoDESI a tiny drop of solvent—approximately 0.2 millimeter in diameter—is delivered to the surface of the target sample and then sucked slowly by capillary action into another tube along with any chemicals picked up from the sample cells. The solution is then analyzed by MS. In this case, the sample was a bacterial colony; it was the first time nanoDESI had been used to repeatedly sample from living bacteria.
The approach generated an unprecedented amount of ...
