The present invention in general relates to a method of localization and structural characterization of peptides in a formaldehyde-fixed paraffin-embedded biological sample using matrix assisted ionization (such as in MALDI). Specifically, the invention relates to the combination of the development of a sample preparation protocol which does not require any enzymatic digestion nor antigen-retrieval steps, with highly sensitive mass spectrometry.

The invention proposes preparing biological samples for spectrometry which contain cell structures and/or whole cells of human or animal origin (e.g. thin human and animal tissue sections) or prokaryotes (e.g. microorganisms), and which require constant relative humidity, in a temperature-controlled gas volume whose humidity is determined by a saturated substance solution, for example a suitable salt solution. The invention exploits a physico-chemical phenomenon called “deliquescence”, which manifests itself by keeping the relative humidity above the saturated substance solution constant with a high degree of precision when a specified temperature is maintained. Pure succinic acid exhibits deliquescence at approx. 99% relative humidity, for example. Since an enormous variety of deliquescent salts and other suitable substances are available, it is possible to find the suitable substance for almost any desired relative humidity, with adjustment of the temperature, where necessary.

A sample preparation workflow to facilitate deep N-glycomics analysis of human serum by capillary electrophoresis with laser induced fluorescence (CE-LIF) detection accommodates the higher sample concentration requirement of electrospray ionization mass spectrometry connected to capillary electrophoresis (CE-ESI-MS). A temperature gradient denaturing protocol is applied on amine functionalized magnetic bead partitioned glycoproteins to avoid precipitation. This also results in the free sugar content of the serum being significantly decreased which allows PNGase F mediated release of the N-linked carbohydrates. The liberated oligosaccharides were tagged with aminopyrene-trisulfonate, utilizing a modified evaporative labeling protocol. This workflow provides appropriate amounts of material for example for use in CE-ESI-MS analysis in negative ionization mode.

The invention relates to a method for the preparation of living, microbial samples and microorganisms for subsequent mass spectrometric measurement and evaluation. Findings which can be derived from such a measurement can particularly serve the faster identification of microorganisms in the microbial sample according to species/subspecies and/or the fast determination of resistance/sensitivity of the microorganisms to antimicrobial substances and/or the further characterization of microorganisms, for example in respect of pathogenicity, virulence and metabolism. According to a preferred embodiment of the invention, the preparation particularly takes place directly on a mass spectrometric sample support.

The invention mainly relates to the mass spectrometric identification of pathogens in blood cultures from bloodstream infections (septicemia). The invention provides a method with which microbial pathogens can be separated in purified form from blood after a relatively brief cultivation in a blood culture flask, without any interfering human proteins or any residual fractions of blood particles such as erythrocytes and leukocytes, and can be directly identified by mass spectrometric measurement of their protein profiles. The method is based on the use of relatively strong tensides to destroy the blood particles by dissolving the weak cell membranes and most of the internal structures of the blood particles; in spite of the fact that tensides are regarded as strong ionization inhibitors in MALDI and other ionization processes required for mass spectrometric measurements. This method allows unknown pathogens to be obtained in their pure form by centrifuging or filtration and to be identified on the taxonomic level of species or subspecies. Problems with DNA from high levels of leukocytes can be resolved by special measures. After sufficient cultivation, the identification in a mass spectrometric laboratory takes only half an hour.

Disclosed herein is a method for verifying the primary structure of a protein through comparative analyses between ion clusters observed in mass spectra and a series of simulated ion clusters deduced from its putative chemical formula. The method comprises the steps of: preparing a protein sample for mass spectrometric analyses; collecting mass spectra of the protein sample; obtaining master ion cluster from a plurality of ion clusters in the mass spectra; producing a series of simulated ion clusters according to the chemical formula of the protein; finding the best fit for the master ion cluster among the series of simulated ion clusters; and verifying if said best-fit simulated ion cluster corresponds to the chemical formula of the protein.

Provided are methods for determining the amount of estradiol in a sample using mass spectrometry. The methods generally involve ionizing estradiol in a sample and detecting and quantifying the amount of the ion to determine the amount of estradiol in the sample.

Methods and devices to capture and analyze aerosolized particles such as protein biomarkers and their truncated proteoforms characteristic of a disease, including a respiratory disease, in exhaled breath to enable rapid detection of diseases are disclosed. The disclosed methods and systems selectively capture aerosolized particles using a packed bed column. The captured particles are then eluted using one or more solvents and analyzed using devices including mass spectrometry.

The invention relates to methods for spectrometric characterization of a test cell substrate. The characterization comprises taxonomic classification and determination of a property of interest of the test cell substrate. The characterization may be based on mass-spectrometric measurement data. The property of interest may be a resistance or susceptibility to a growth-influencing factor. After comparing first spectrometric measurement data of the test cell substrate with a provided reference library, a sub-library is created comprising those reference datasets from the reference library that are classified as allowing a taxonomic classification of the test cell substrate. Second spectrometric measurement data after a second preparation of the test cell substrate under conditions that serve to determine a property of interest of the test cell substrate is compared with the sub-library and allow a reliable determination of the property of interest.

Disclosed is a method of desorbing an adsorbed material by subjecting to energy a diazirine adsorbed on a solid surface or a layer on the solid surface, which causes the diazirine to form a carbene and nitrogen gas; and using the energy of the resultant nitrogen gas to desorb the adsorbed material from the solid surface or a layer on the same. Also disclosed is a method of reacting the resultant carbene with (a) a material in the gas phase proximal to the first solid surface; (b) a material adsorbed on a second solid surface proximal to the first solid surface; or (c) a second solid surface proximal to the first solid surface.