1 applications
1.1 biochemistry
1.2 organic chemistry
1.3 polymers
1.4 microbiology
1.5 medicine
applications
biochemistry
in proteomics, maldi used rapid identification of proteins isolated using gel electrophoresis: sds-page, size exclusion chromatography, affinity chromatography, strong/weak ion exchange, isotope coded protein labelling (icpl), , two-dimensional gel electrophoresis. peptide mass fingerprinting popular analytical application of maldi-tof mass spectrometers. maldi tof/tof mass spectrometers used reveal amino acid sequence of peptides using post-source decay or high energy collision-induced dissociation (further use see mass spectrometry).
loss of sialic acid has been identified in papers when dhb has been used matrix maldi ms analysis of glycosylated peptides. using sinapinic acid, 4-hcca , dhb matrices, s. martin studied loss of sialic acid in glycosylated peptides metastable decay in maldi/tof in linear mode , reflector mode. group @ shimadzu corporation derivatized sialic acid amidation reaction way improve detection sensitivity , demonstrated ionic liquid matrix reduces loss of sialic acid during maldi/tof ms analysis of sialylated oligosaccharides. thap, dhap, , mixture of 2-aza-2-thiothymine , phenylhydrazine have been identified matrices used minimize loss of sialic acid during maldi ms analysis of glycosylated peptides.
it has been reported reduction in loss of post-translational modifications can accomplished if ir maldi used instead of uv maldi
in molecular biology, mixture of 5-methoxysalicylic acid , spermine can used matrix oligonucleotides analysis in maldi mass spectrometry, instance after oligonucleotide synthesis.
organic chemistry
some synthetic macromolecules, such catenanes , rotaxanes, dendrimers , hyperbranched polymers, , other assemblies, have molecular weights extending thousands or tens of thousands, ionization techniques have difficulty producing molecular ions. maldi simple , fast analytical method can allow chemists rapidly analyze results of such syntheses , verify results.
polymers
in polymer chemistry maldi can used determine molar mass distribution. polymers polydispersity greater 1.2 difficult characterize maldi due signal intensity discrimination against higher mass oligomers.
a matrix polymers dithranol or agtfa. sample must first mixed dithranol , agtfa added afterwards; otherwise sample precipitate out of solution.
microbiology
maldi/tof spectra used identification of micro-organisms such bacteria or fungi. portion of colony of microbe in question placed onto sample target , overlaid matrix. mass spectra generated analyzed dedicated software , compared stored profiles. species diagnosis procedure faster, more accurate , cheaper other procedures based on immunological or biochemical tests. maldi/tof becoming standard method species identification in medical microbiological laboratories.
one main advantage on other microbiological identification methods ability rapidly , reliably identify, @ low cost, wide variety of microorganisms directly selective medium used isolate them. absence of need purify suspect or presumptive colony allows faster turn-around times.
another advantage potential predict antibiotic susceptibility of bacteria. single mass spectral peak can predict methicillin resistance of staphylococcus aureus maldi can detect carbapenemase of carbapenem-resistant enterobacteriaceae, including acinetobacter baumannii , klebsiella pneumoniae. however, proteins mediate antibiotic resistance larger maldi-tof´s 2000-20,000 da range protein peak interpretation , occasionally, in 2011 kpc outbreak @ nih, correlation between peak , resistance conferring protein can made.
medicine
maldi/tof spectra utilized in tandem other analysis , spectroscopy techniques in diagnosis of diseases. maldi/tof diagnostic tool potential because allows rapid identification of proteins , changes proteins without cost or computing power of sequencing nor skill or time needed solve crystal structure in x-ray crystallography.
one example of necrotizing enterocolitis (nec), devastating disease affects bowels of premature infants. symptoms of nec similar of sepsis, , many infants die awaiting diagnosis , treatment. maldi/tof used analyze fecal samples , find differences between mutant , functional protein responsible nec. there hope similar technique used quick, diagnostic tool not require sequencing.
another example of diagnostic power of maldi/tof in area of cancer. pancreatic cancer remains 1 of deadly , difficult diagnose cancers. impaired cellular signaling due mutations in membrane proteins has been long suspected contribute pancreatic cancer. maldi/tof has been used identify membrane protein associated pancreatic cancer , @ 1 point may serve detection technique.
maldi/tof can potentially used dictate treatment diagnosis. maldi/tof serves method determining drug resistance of bacteria, β-lactamases (penicillin family). maldi/tof detects presence of carbapenemases, indicates drug resistance standard antibiotics. predicted serve method identifying bacterium drug resistant in little 3 hours. technique physicians decide whether prescribe more aggressive antibiotics initially.
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