Infrared MALDI Mass Spectrometry with Laser-Induced Postionization for Imaging of Bacterial Colonies.

Ultraviolet matrix-assisted laser desorption ionization mass spectrometry imaging (UV-MALDI-MSI) is a powerful tool to visualize bacterial metabolites in microbial colonies and in biofilms. However, a challenge for the method is the efficient extraction of analytes from deeper within the bacterial colonies and from the cytoplasm of individual cells during the matrix coating step. Here, we used a pulsed infrared (IR) laser of 2.

Advanced Methods for MALDI-MS Imaging of the Chemical Communication in Microbial Communities.

Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) is increasingly used to visualize the chemical communication between microorganisms. However, to fully exploit the potential of this label-free technique, crucial methodological advances are still needed. In particular, with current microbial MALDI-MSI methods chemical coverage is strongly limited to well ionizing compounds and a safe MSI-compatible inactivation of microbial viability and quenching of metabolism is not possible.