In the past decade, clinical microbiology underwent revolutionary changes in methods used to identify microorganisms, a transition from slow and traditional microbial identification algorithms to rapid molecular methods and mass spectrometry (MS). Earlier, MS was clinically used as a highly complex method that was adapted for protein-centered analysis of samples in chemistry laboratories. Recently, a paradigm-shift happened when matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) MS was implemented to be used in microbiology laboratories for rapid and robust methods for accurate microbial identification. Two instrument platforms, marketed by well-established manufacturers, are beginning to displace automated phenotypic identification instruments and in some cases even genetic sequence-based identification practices. This review summarizes the current role of MALDI-TOF MS in clinical research, in diagnostic clinical microbiology laboratories, and serves as an introduction to MALDI-TOF MS, highlighting research associated with sample preparation, algorithms, interpretations, and limitations. Currently available MALDI-TOF MS instruments as well as software platforms that support the use of MALDI-TOF with direct specimens have been discussed in this review. Finally, clinical laboratories are consistently striving to extend the potential of these new methods, often in partnership with developmental scientists, resulting in novel technologies, such as MALDI-TOF MS, which could shape and define the diagnostic landscape for years to come.
Chemistry ; Mass Spectrometry

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized the identification of microbial species in clinical microbiology laboratories. MALDI-TOF-MS has swiftly become the new gold-standard method owing to its key advantages of simplicity and robustness. However, as with all new methods, adoption of the MALDI-TOF MS approach is still not widespread. Optimal sample preparation has not yet been achieved for several applications, and there are continuing discussions on the need for improved database quality and the inclusion of additional microbial species. New applications such as in the field of antimicrobial susceptibility testing have been proposed but not yet translated to the level of ease and reproducibility that one should expect in routine diagnostic systems. Finally, during routine identification testing, unexpected results are regularly obtained, and the best methods for transmitting these results into clinical care are still evolving. We here discuss the success of MALDI-TOF MS in clinical microbiology and highlight fields of application that are still amenable to improvement.
Classification ; Mass Spectrometry* ; Methods

Thermal proteome profiling (TPP) is a combination of cellular thermal shift assay (CETSA) and quantitative mass spectrometry (MS), also termed as MS-CETSA. TPP determines the stability of the entire proteome by measuring the content of soluble proteins in cells or cell lysates at different heating temperatures. Proteins can change their thermostability when interacting with small molecules (e.g., drugs or metabolites), nucleic acids, or other proteins or posttranslational modification, while TPP can identify target proteins based on the difference in thermostability with or without ligand-binding. At present, TPP has been applied to identify the targets and off-targets of drugs and interrogate protein-metabolite and protein-protein interactions. Due to limited understanding of this technology, this review introduced the principles, methods, applications, advantages and limitations of TPP.
Proteome ; Mass Spectrometry

The fragmentation pathways of the three ginkgolides (ginkgolides A, ginkgolides B, ginkgolides C) have been studied with high resolution and high mass accuracy using quadrupole time-of-flight mass spectrometry in negative ion mode in this paper. The results indicate that the three ginkgolides have similar fragmentation pathways, including four kinds of common cleavage pathways and one common characteristic ion. In high quality regions, the typical fragmentation pathways of the three ginkgolides are lactone ring opening with continuous loss of CO, CO₂,and loss of H₂O. In low quality regions, the common characteristic fragment ion of the three ginkgolides at 72.993 6 is formed by C rings cleavage. Also, the common fragment ions of ginkgolides A and ginkgolides B at 141.018 8, 125.023 8, 113.024 0, 97.029 1 are formed by A rings cleavage. The study of fragmentation pathways could be adopted for the structural identification of the ginkgolides and their metabolites.
Ginkgolides ; chemistry ; Mass Spectrometry ; Spectrometry, Mass, Electrospray Ionization

Because of the exist of complex matrix, the confirming indicators of qualitative results for toxic substances in biological samples by chromatography-mass spectrometry are different from that in non-biological samples. Even in biological samples, the confirming indicators are different in various application areas. This paper reviews the similarities and differences of confirming indicators for the analyte in biological samples by chromatography-mass spectrometry in the field of forensic toxicological analysis and other application areas. These confirming indicators include retention time （RT）, relative retention time （RRT）, signal to noise （S/N）, characteristic ions, relative abundance of characteristic ions, parent ion-daughter ion pair and abundance ratio of ion pair, etc.
Chromatography ; Forensic Toxicology ; Gas Chromatography-Mass Spectrometry ; Mass Spectrometry

Species identification is an important item to characterize unidentified bacterial pathogens in developing and managing bacterial resources. In this study, unidentified pathogens based on the results of an automated identification system were identified using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALD-TOF MS) and 16S rRNA gene analysis for development of national resources in the National Culture Collection for Pathogens (NCCP) in Korea. A total of 437 unidentified strains from branch banks of the NCCP were collected, and 16S rRNA and dnaJ gene sequencing, as well as MALDI-TOF MS analysis were performed to identify bacterial species. The mass spectra extracted were analyzed. Twelve strains exhibiting less than 98.65% similarity in 16S rRNA gene were selected as the primary candidates for novel species, and 21 strains exhibiting 98.65~99.0% similarity in 16S rRNA gene were selected as possible candidates for novel species. Among them, strain 32, belonging to Dermabacter sp., was finally selected as a possible strain representing a novel species and 14 unidentified bacterial strains using automated phenotypic identification system were newly registered at NCCP. The present study showed that unidentified pathogens using the automated phenotypic identification system were efficiently identified using the combination of MALDI-TOF MS and 16S rRNA gene analysis, and developed to the national resources in NCCP.
Genes, rRNA* ; Korea ; Mass Spectrometry

OBJECTIVETo establish a method to determine total bromine in urine.

METHODDiluted urine samples were directly introduced into ICP-MS then quantized by standard curve.

RESULTTotal bromine in urine was linear within 1.0~50 mg/L with r > 0.999, When spiked at a concentration of 0.020 mg/L, 0.050 mg/L, 0.150 mg/L, the recovery was 95%~98%, intra-assay precision was 1.4% 3.2%, inter-assay precision was 3.4% to 5.0%. Urine could store in -20 °C refrigerator 3 months without any bromine loss.

CONCLUSIONUsing ICP-MS to determine the urinary total bromine, the method is fast, accurate, wide linear range of features, could meet with the requirement of Part 5 of occupational health standards guide: Method determination of chemical substances in biological materials (GBZ/T 210.5-2008), a strong competitive advantage in a wide range of survey, suitable for promotion.

No abstract available.
Diagnosis ; Gas Chromatography-Mass Spectrometry

The Clinical Mass Spectrometry Research Committee (CMSRC), in affiliation with the Korean Society of Clinical Chemistry (KSCC), conducted a questionnaire survey on opinions about the general status of clinical mass spectrometric analysis in Korea. As a result, we understand that this field has passed through the introductory stage and is settled as a field of clinical laboratory testing in Korea, with the number of new laboratories performing mass spectrometric analysis being low. In spite of the many difficulties in introducing and operating clinical mass spectrometric analysis, there is a strong interest in this field, and even though further expansion is expected, there are still many issues to be resolved. In the future, it will be necessary to make concrete and thorough efforts to further develop the laboratory tests using clinical mass spectrometric analysis in Korea, centering on the CMSRC affiliated with the KSCC.
Chemistry, Clinical ; Korea ; Mass Spectrometry

No abstract available.
Gas Chromatography-Mass Spectrometry* ; Mass Screening* ; Neuroblastoma*