MALDI Mass Spectrometry Imaging: A Potential Game-Changer in a Modern Microbiology

Abstract

Nowadays, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) is routinely implemented as the reference method for the swift and straightforward identification of microorganisms. However, this method is not flawless and there is a need to upgrade the current methodology in order to free the routine lab from incubation time and shift from a culture-dependent to an even faster independent culture system. Over the last two decades, mass spectrometry imaging (MSI) gained tremendous popularity in life sciences, including microbiology, due to its ability to simultaneously detect biomolecules, as well as their spatial distribution, in complex samples. Through this literature review, we summarize the latest applications of MALDI-MSI in microbiology. In addition, we discuss the challenges and avenues of exploration for applying MSI to solve current MALDI-TOF MS limits in routine and research laboratories.

A Comprehensive Comparison of Tissue Processing Methods for High-Quality MALDI Imaging of Lipids in Reconstructed Human Epidermis

“…Interestingly, there is currently no standard regarding the choice of substrate for the MALDI imaging of biological tissues despite this being a crucial step in the generation of ions (since the conductivity affects the ionization/transmission of ionized molecules, e.g., lipids). This observation was also made by Feucherolles and Frache during their analysis of microbiological applications . Various substrates have been used to analyze lipids in skin samples, including aluminum plates, gold-coated MALDI plates, as well as conventional microscope glass slides. − Glass slides are mainly used so that histological staining, e.g., hematoxylin and eosin, can be performed in parallel to MALDI imaging.…”

Mass spectrometry-based techniques for single-cell analysis

“…under vacuum conditions, the crystals are treated with a laser to transform and ionize the sample. [40][41][42] The basic principle of matrix-free LDI is similar to MALDI, but matrix-free LDI does not require the matrix to co-crystallize after mixing with the sample. Instead, it requires a surface that can transmit laser energy to the sample.…”

State-of-the-art mass spectrometry imaging applications in biomedical research

“…142,143 The recent review by Feucherolles and Frache comprehensively summarizes the developments of MSI in the field of microbiology. 144…”