scholarly journals MALDI-TOF masa-espektrometria ezagutzen

Author(s):  
Antonio Veloso

Gaur egun, nahiko informazio ageria ematen dute biomolekulak eta materialak karakterizatzeko erabiltzen diren laborategi-teknika analitikoek, baina azaldu ezin diren efektuak edo emaitzak lortzen dira askotan. Horregatik, informazio hau lortzeko, hau da, molekulen mikroegiturak karakterizatzeko edota gertatu diren kutsadurak ezagutzeko ere, gero eta gehiago hedatzen ari da teknika bat, Matrix Assisted Laser Desorption-Ionization/Time of Flight Mass Spectrometry (MALDI/TOF-MS) izenekoa, edo laserraren bidezko desortzio-ionizazio matrizez lagundua/hegaldi-denbora masa-espektrometria teknika. Masa-espektrometria delako karakterizazio teknika hau hainbat alorretara hedatu da, masa molarra jakitea ahalbidetzen duelako inolako zatiketarik gabe eta, aldi berean, ehun edo material baten banaketaren berri ematen duelako Imaging Mass Spectrometry (IMS) edo masa-espektrometriaren bidezko irudia deritzon teknikari esker. Lan honek helburu hartuko du teknika berri honen oinarriak eta aplikazioak azaltzea eta aztertzea.

2012 ◽  
Vol 90 (9) ◽  
pp. 1117-1127 ◽  
Author(s):  
E.L. Pannkuk ◽  
D.F. Gilmore ◽  
B.J. Savary ◽  
T.S. Risch

Lipids secreted from sebaceous glands in bat integument may play a role in determining host pathogenicity by the fungus Geomyces destructans in white-nose syndrome (WNS). To investigate this, we have determined the triacylglycerol (TAG) profiles for three bat species: eastern red bats ( Lasiurus borealis (Müller, 1776)), evening bats ( Nycticeius humeralis (Rafinesque, 1818)), and big brown bats ( Eptesicus fuscus (Beauvois, 1796)). Neutral lipids extracted from the hair and wing tissue were fractionated by preparative thin-layer chromatography (TLC) into four major lipid bands corresponding to cholesterol, free fatty acids (FFAs), TAGs, and sterol–wax esters. Densitometry showed higher proportions of TAGs in hair than from wing tissue. TAG bands were recovered and analyzed by matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI–TOF MS). Mass spectra showed sodiated TAG species with variable fatty acyl (FA) moieties range from m/z 715.6–911.8. High intensity ion peaks were consistent with 16:0 and 18:1 as dominant FA moieties, and these were identified as palmitic and oleic acids, respectively, by liquid chromatography electrospray ionization mass spectrometry. We determined significant differences in TAG profiles between three bat species by MALDI–TOF MS, providing the first description of integumentary lipids in bats. In this study, we performed the first TAG profiling of bats, which suggest such profiles may be species-specific in bats.


2005 ◽  
Vol 51 (7) ◽  
pp. 1123-1131 ◽  
Author(s):  
Yoon Jun Kim ◽  
Soo-Ok Kim ◽  
Hyun Jae Chung ◽  
Mi Sun Jee ◽  
Byeong Gwan Kim ◽  
...  

Abstract Background: Identifying hepatitis C virus (HCV) genotypes has become increasingly important for determining clinical course and the outcome of antiviral therapy. Here we describe the development of restriction fragment mass polymorphism (RFMP) analysis, a novel matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) assay suitable for high-throughput, sensitive, specific genotyping of multiple HCV species. Methods: The assay is based on PCR amplification and mass measurement of oligonucleotides containing genotype-specific motifs in the 5′ untranslated region, into which a type IIS restriction endonuclease recognition was introduced by PCR amplification. Enzymatic cleavage of the products led to excision of multiple oligonucleotide fragments representing variable regions whose masses were determined by MALDI-TOF MS. Results: The RFMP assay identified viral genotypes present at concentrations as low as 0.5% and reliably determined their relative abundance. When sera from 318 patients were analyzed, the RFMP assay exhibited 100% concordance with results obtained by clonal sequencing and identified mixed-genotype infections in 22% of the samples, in addition to several subtype variants. Conclusions: The RFMP assay has practical advantages over existing methods, including better quantitative detection of mixed populations and detection of genotype variants without need for population-based cloning, enabling reliable viral genotyping in laboratories and efficient study of the relationship between viral genotypes and clinical outcome.


2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Joachim Spergser ◽  
Claudia Hess ◽  
Igor Loncaric ◽  
Ana S. Ramírez

ABSTRACTIn veterinary diagnostic laboratories, identification of mycoplasmas is achieved by demanding, cost-intensive, and time-consuming methods that rely on antigenic or genetic identification. Since matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) seems to represent a promising alternative to the currently practiced cumbersome diagnostics, we assessed its applicability for the identification of almost all mycoplasma species isolated from vertebrate animals so far. For generating main spectrum profiles (MSPs), the type strains of 98Mycoplasma, 11Acholeplasma, and 5Ureaplasmaspecies and, in the case of 69 species, 1 to 7 clinical isolates were used. To complete the database, 3 to 7 representatives of 23 undescribedMycoplasmaspecies isolated from livestock, companion animals, and wildlife were also analyzed. A large in-house library containing 530 MSPs was generated, and the diversity of spectra within a species was assessed by constructing dendrograms based on a similarity matrix. All strains of a given species formed cohesive clusters clearly distinct from all other species. In addition, phylogenetically closely related species also clustered closely but were separated accurately, indicating that the established database was highly robust, reproducible, and reliable. Further validation of the in-house mycoplasma library using 335 independent clinical isolates of 32 mycoplasma species confirmed the robustness of the established database by achieving reliable species identification with log scores of ≥1.80. In summary, MALDI-TOF MS proved to be an excellent method for the identification and differentiation of animal mycoplasmas, combining convenience, ease, speed, precision, and low running costs. Furthermore, this method is a powerful and supportive tool for the taxonomic resolution of animal mycoplasmas.


2019 ◽  
Vol 36 (No. 6) ◽  
pp. 452-458 ◽  
Author(s):  
Štěpán Koudelka ◽  
Tereza Gelbíčová ◽  
Markéta Procházková ◽  
Renáta Karpíšková

The identification of Listeria species, lineages and serotypes remains a crucial issue not only in epidemic surveys, but also in monitoring of the diversity of bacteria in the food chain. The aim of this study was identification of L. monocytogenes strains at lineage and serotype level using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The performance of MALDI-TOF MS was tested to identify L. monocytogenes into two lineages (I and II) and four serotypes (1/2a, 1/2b, 1/2c and 4b) the most commonly found in humans and food. Total of 227 L. monocytogenes strains from different sources were subjected to the study. Some of strains (112) were used for main spectrum profile (MSP) library creation. Other strains of interest (115) were then correctly identified on the lineage level comparing with the library by MALDI-TOF MS analysis using Biotyper (90%) and ClinPro Tools (100%) software. The serotype identification with 55.7% (Biotyper) and 67.8% (ClinPro Tools) accuracy is rather a proof that under given conditions the method has not big potential to be used for serotyping. However, MALDI-TOF MS has a potential to identify lineages of L. monocytogenes of food and human origin.


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