1 research outputs found
Constant-Distance Mode Nanospray Desorption Electrospray Ionization Mass Spectrometry Imaging of Biological Samples with Complex Topography
A new
approach for constant-distance mode mass spectrometry imaging
(MSI) of biological samples using nanospray desorption electrospray
ionization (nano-DESI) was developed by integrating a shear-force
probe with the nano-DESI probe. The technical concept and basic instrumental
setup, as well as the general operation of the system are described.
Mechanical dampening of resonant oscillations due to the presence
of shear forces between the probe and the sample surface enabled the
constant-distance imaging mode via a computer-controlled closed-feedback
loop. The capability of simultaneous chemical and topographic imaging
of complex biological samples is demonstrated using living Bacillus subtilis ATCC 49760 colonies on agar plates.
The constant-distance mode nano-DESI MSI enabled imaging of many metabolites,
including nonribosomal peptides (surfactin, plipastatin, and iturin)
on the surface of living bacterial colonies, ranging in diameter from
10 to 13 mm, with height variations up to 0.8 mm above the agar plate.
Co-registration of ion images to topographic images provided higher-contrast
images. Based on this effort, constant-mode nano-DESI MSI proved to
be ideally suited for imaging biological samples of complex topography
in their native states