• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.54-58
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• 2017

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS) is one of the powerful methods that enable analysis of small molecules as well as large molecules up to about 500,000 Da without severe fragmentation. MALDI-TOF MS, thus, has been a very useful an analytical tool for the confirmation of synthetic molecules, probing PTMs, and identifying structures of a given protein. In recent nuclear medicine, MALDI-TOF MS liner ion mode helps researcher calculate the average number of chelator(or linkage) per an antibody conjugate, such as DOTA-(or DFO-) trastuzumab for labeling a medical radioisotope. This simple technique can be utilized to improve the labeling method and control the quality at the development of antibody-based radiopharmaceuticals, which is very effected to diagnosis and therapy for in vivo tumor cells, with radioisotopes like $^{89}Zr$, $^{64}Cu$, and 177Lu. To minimize the error, MALDI-TOF MS measurement is repeatedly performed for each sample in this study, and external calibration is carried out after data collection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.260-262
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• 2003

A thermal vapor deposition method for crystallization of insoluble analytes with matrix is established as a new sample preparation method for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). A mixture of mono, bis and tris(p-ethyl benzylidene) sorbitols was incorporated into microcrystals of ferulic acid, which was confirmed by confocal micrographs. Molecular masses of sorbitol derivatives were determined in this way by MALDI-MS without thermal decomposition.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.311-313
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• 2003

A thermal vapor deposition method for crystallization of insoluble analysis with matrix is established as a new sample preparation method for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). A mixture of mono, bis and tris(p-ethyl benzylidene) sorbitols was incorporated into microcrystals of ferulic acid, which was confirmed by confocal micrographs. Molecular masses of sorbitol derivatives were determined in this way by MALDI-MS without thermal decomposition.

• Mass Spectrometry Letters
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• v.5 no.2
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• pp.49-51
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• 2014

The effectiveness of tertiary matrices composed of the combination of three common matrices (dihydrobenzoic acid (DHB), ${\alpha}$-cyano-4-hydroxycinnamic acid (CHCA), and sinapinic acid (SA)) was compared with that of single or binary matrices in the analysis of polyethylene glycol (PEG) polymers ranging from 1400 to 10000 Da using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A tertiary matrix of 2,5-DHB+CHCA+SA was the most effective in terms of S/N ratios. CHCA and CHCA+SA produced the highest S/N ratios among the single matrices and the binary matrices, respectively. The improvement observed when using a tertiary matrix in analyses of PEG polymers by MALDI-TOF MS is believed to be due to the uniform morphology of the MALDI sample spots and synergistic effects arising from the mixture of the three matrix materials.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.480-507
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• 2003

A rapid and efficient method for analyzing the nonionic surfactants and silicone polymers, which control the shape and characteristics of cosmetic products and give influence on product quality, has been developed using Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI- TOF IMS). The MALDI-TOF/MS could easily and effectively determine the molecular weight distribution and monomer units of nonionic surfactants. As a result, creating a library of mass spectrum data of surfactants used in cosmetic products using MALDI-TOF/MS and analyzing surfactants extracted from the products may become a useful method for detailed structural characterization of the surfactants. Furthermore, the MALDI-TOF/MS analysis was effective in obtaining the spectrum of silicone polymers from which the molecular weight distribution could be determined. The repetition units and structural data could also be obtained through molecular mass peaks. Additionally, the monomer ratio and terminal groups as properties of silicone copolymers could be determined

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.131-137
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• 2012

Rapid and reliable identification of microorganisms is a key for tracing the relationship between the target bacteria and related infectious diseases. Various identification methods such as classical phenotypic analysis, numerical taxonomic analysis, and DNA sequencing have been widely used to classify microorganisms in milk and dairy products. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) identifies targeted bacteria in milk and milk products. Several studies have demonstrated that MALDI-TOF MS identification is an efficient and inexpensive method for the rapid and routine identification of isolated bacteria. MALDI-TOF MS could provide accurate identification of bacteria in milk and milk products at the serotype or strain level and enable antibiotic resistance profiling within minutes.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.887-896
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• 2019

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based pathogen identification relies on the ribosomal protein spectra provided in the proprietary database. Although these mass spectra can discern various pathogens at species level, the spectra-based method still has limitations in identifying closely-related microbial species. In this study, to overcome the limits of the current MALDI-TOF MS identification method using ribosomal protein spectra, we applied MALDI-TOF MS of low-mass profiling to the identification of two genetically related Bacillus species, the food-borne pathogen Bacillus cereus, and the insect pathogen Bacillus thuringiensis. The mass spectra of small molecules from 17 type strains of two bacilli were compared to the morphological, biochemical, and genetic identification methods of pathogens. The specific mass peaks in the low-mass range (m/z 500-3,000) successfully identified various closely-related strains belonging to these two reference species. The intensity profiles of the MALDI-TOF mass spectra clearly revealed the differences between the two genetically-related species at strain level. We suggest that small molecules with low molecular weight, 714.2 and 906.5 m/z can be potential mass biomarkers used for reliable identification of B. cereus and B. thuringiensis.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2143-2147
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• 2013

Matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is a very effective method for lipid mass fingerprinting. However, MALDI MS suffered from spectral complexities, differential ionization efficiencies, and poor reproducibility when analyzing complex lipid mixtures without prior separation steps. Here, we aimed to find optimal MALDI sample preparation methods which enable selective or class-wide mass fingerprinting of two totally different lipid classes. In order to achieve this, various matrices with additives were tested against the mixture of phosphatidylcholine (PC) and cerebrosides (Cers) which are abundant in animal brain tissues and also of great interests in disease biology. Our results showed that, from complex lipid mixtures, 2,4,6-trihydroxyacetophenone (THAP) with $NaNO_3$ was a useful MALDI matrix for the class-wide fingerprinting of PC and Cers. In contrast, THAP efficiently generated PC-focused profiles and graphene oxide (GO) with $NaNO_3$ provided Cer-only profiles with reduced spectral complexity.

• KSBB Journal
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• v.30 no.5
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• pp.230-238
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• 2015

Abnormal glycosylation can significantly affect the intrinsic functions (i.e., stability and solubility) of proteins and the extrinsic protein interactions with other biomolecules. For example, recombinant glycoprotein therapeutics needs proper glycosylation for optimal drug efficacy. Therefore, there has been a strong demand for rapid, sensitive and high-through-put glycomics tools for real-time monitoring and fast validation of the biotherapeutics glycosylation. Although liquid chromatography tandem mass spectrometry (LC-MS/MS) is one of the most powerful tools for the characterization of glycan structures, it is generally time consuming and requires highly skilled personnel to collect the data and analyze the results. Recently, as an alternative method, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS), which is a fast, robust and easy-to-use instrumentation, has been used for quantitative glycomics with various chemical derivatization techniques. In this review, we highlight the recent advances in MALDI-MS based quantitative glycan analysis according to the chemical derivatization strategies. Moreover, we address the application of MALDI-MS for high-throughput glycan analysis in many fields of clinical and biochemical engineering.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.149-154
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• 2011

Matrix assisted laser desorption ionization (MALDI) mass spectrometry is commonly used to analyze biological molecules such as proteins, peptides and lipids from cells or tissue. Recently MALDI Imaging mass spectrometry (IMS) has been widely applied for the identification of different drugs and their metabolites in tissue. This special feature has made MALDI-MS a common choice for investigation of the molecular histology of pathological samples as well as an important alternative to other conventional imaging methods. The basic advantages of MALDI-IMS are its simple technique, rapid acquisition, increased sensitivity and most prominently, its capacity for direct tissue analysis without prior sample preparation. Moreover, with ms/ms analysis, it is possible to acquire structural information of known or unknown analytes directly from tissue sections. In recent years, MALDI-IMS has made enormous advances in the pathological field. Indeed, it is now possible to identify various changes in biological components due to disease states directly on tissue as well as to analyze the effect of treated drugs. In this review, we focus on the advantages of MALDI tissue imaging over traditional methods and highlight some motivating findings that are significant in pathological studies.