Matrix-assisted laser desorption ionisation (MALDI) mass spectrometry (MS): basics and clinical applications

Abstract

<jats:title>Abstract</jats:title><jats:sec id="j_cclm-2019-0868_s_999_w2aab3b8c54b1b7b1aab1c16b1Aa"><jats:title>Background</jats:title><jats:p>Matrix-assisted laser desorption ionisation (MALDI) mass spectrometry (MS) has been used for more than 30 years. Compared with other analytical techniques, it offers ease of use, high throughput, robustness, cost-effectiveness, rapid analysis and sensitivity. As advantages, current clinical techniques (e.g. immunoassays) are unable to directly measure the biomarker; rather, they measure secondary signals. MALDI-MS has been extensively researched for clinical applications, and it is set for a breakthrough as a routine tool for clinical diagnostics.</jats:p></jats:sec><jats:sec id="j_cclm-2019-0868_s_998_w2aab3b8c54b1b7b1aab1c16b2Aa"><jats:title>Content</jats:title><jats:p>This review reports on the principles of MALDI-MS and discusses current clinical applications and the future clinical prospects for MALDI-MS. Furthermore, the review assesses the limitations currently experienced in clinical assays, the advantages and the impact of MALDI-MS to transform clinical laboratories.</jats:p></jats:sec><jats:sec id="j_cclm-2019-0868_s_997_w2aab3b8c54b1b7b1aab1c16b3Aa"><jats:title>Summary</jats:title><jats:p>MALDI-MS is widely used in clinical microbiology for the screening of microbial isolates; however, there is scope to apply MALDI-MS in the diagnosis, prognosis, therapeutic drug monitoring and biopsy imaging in many diseases.</jats:p></jats:sec><jats:sec id="j_cclm-2019-0868_s_996_w2aab3b8c54b1b7b1aab1c16b4Aa"><jats:title>Outlook</jats:title><jats:p>There is considerable potential for MALDI-MS in clinic as a tool for screening, profiling and imaging because of its high sensitivity and specificity over alternative techniques.</jats:p></jats:sec>

High-Throughput Detection and Characterization of Antimicrobial Resistant Enterococcus sp. Isolates from GI Tracts of European Starlings Visiting Concentrated Animal Feeding Operations

“…are commonly used as antimicrobial resistance indicators [ 16 ]. While MALDI-TOF MS has become an established identification method in clinical laboratories [ 17 , 18 , 19 ], the results of this study further demonstrate the utility of MALDI-TOF MS for monitoring of AMR indicators Enterococcus spp. in the environment and wildlife.…”

Synergizing the potential of bacterial genomics and metabolomics to find novel antibiotics

“…MALDI ionization for example, often employed in imaging workflows, has shown its potential to expand the detectable secondary metabolome both in terms of visualizing ions with an alternative ionization source but also in terms of observing microorganisms growing on a solid support. 39 This ionization technique is extremely useful for tapping into the bacterial secondary metabolome of bacteria, which are hard to ferment in liquid media. MALDI imaging was employed in metabolomics experiments in Frankia sp., a group of actinobacteria difficult to cultivate in liquid media, making fermentation for isolation of any novel natural product a particularly challenging task.…”

Insight to Functional Conformation and Noncovalent Interactions of Protein-Protein Assembly Using MALDI Mass Spectrometry

“…Even though the high energy of the laser, MALDI can preserve noncovalent interactions [5], and yields stoichiometric information of the protein-protein complex [16]. A general advantage of implementing MALDI in analytical procedures is also a user-friendly sample preparation (small sample volumes, no complicated protocols, and high salt tolerance), compatible with high-throughput screening procedures [85] and clinical applications [86]. On the other hand, special and expensive detectors such as ion conversion dynode (ICD), which is the only commercially available high-mass detector, are required for the detection of intact protein-protein complexes with very good sensitivity [87].…”