A programmed computer functioning as a classifier operates on mass spectral data obtained from a blood-based patient sample to predict indolence or aggressiveness of prostate cancer. Methods of generating the classifier and conducting a test on a blood-based sample from a prostate cancer patient using the classifier are described.

The present invention relates to the field of nephrology. More specifically, the present invention provides methods and compositions useful for more precisely estimating glomerular filtration rate (GFR). In a specific embodiment, a method for calculating the estimated glomerular filtration rate (eGFR) in a patient comprises the steps of (a) measuring the level of one or more metabolites using mass spectrometry from a blood sample obtained from the patient; and (b) calculating the eGFR using an algorithm that utilizes the measured levels of the one or more metabolites.

A method to measure heat damage of keratin fibers comprising eluting a peptide from a hair sample with an aqueous solution; extracting the peptide using a suitable solvent sample; analyzing the peptide samples with MALDI-MS; resulting in peptide results; identifying presence of a marker peptide and identifying the m/z ratio for the peptide.

A method for modification of solid substrates with proteins for efficient surface preconcentration of an analyte from multi-component samples before the detection based on desorption-ionization mass spectrometry and immunochemical assays. The claimed subject is a method of modification of surfaces used as substrates for desorption-ionization mass spectrometry and immuno-chemical assays. The method is based on electronebulization (electrospraying) of protein solution, depending on the intended application either enzymes, lectins, or antibodies. The formed charged electrospray is dried in real time by its passing through an evaporation compartment and the resulting beam of desolvated ions impacts onto the surface and binds to it firmly. Such modified surface can be then used for a selective interaction with an affinity partner of the deposited protein, its preconcentration or enzymatic modification followed by an analysis by means of desorption-ionization mass spectrometry or immunochemical assays.

Disclosed herein is a method of analysing a tissue sample. The method comprises identifying one or more regions of interest within the tissue sample based on a tissue stain that has been applied to the tissue sample. Analyte material is then generated from the one or more regions of interest identified based on the tissue stain using a direct surface sampling probe (10), which analyte material is then received at a sampling inlet (30) and passed towards a mass and/or ion mobility spectrometer (50) for analysis.

The invention provides methods for quantifying biomolecules, such as polypeptides in mass spectrometric analysis. The methods include use of a biomolecule standard having at least one atomic isotope different than that of the naturally occurring isotopes in the biomolecule of interest. Methods of the present invention also include methods for quantifying biomolecules where the copy biomolecule standard is made by expressing the biomolecule using a recombinant cell. Further included are the biomolecule standards themselves, method for making such standards, kits, systems, reagents, and engineered cells relating to the use of biomolecule standards in mass spectrometric analysis.

The current disclosure provides for specific peptides from the Secreted Protein Acidic and Rich in Cysteine (SPARC) protein and the derived ionization characteristics of those peptides that are advantageous for quantifying the SPARC directly in formalin fixed biological samples by the method of Selected Reaction Monitoring (SRM) mass spectrometry. Such fixed biological samples include: formalin-fixed tissue/cells, formalin-fixed/paraffin embedded (FFPE) tissue/cells, FFPE tissue blocks and cells from those blocks, and formalin fixed and paraffin embedded tissue culture cells. SPARC protein is quantitated in biological samples by the method of SRM/MRM mass spectrometry by quantitating one or more of the peptides described herein. The peptides can be quantitated if they reside in a modified or an unmodified form. Examples of potentially modified forms of an SPARC peptides include those bearing phosphorylation of a tyrosine, threonine, serine, and/or other amino acid residues within the peptide sequence.

An analysis method includes: acquiring data corresponding to a mass spectrum obtained by subjecting a sample containing a microorganism to mass spectrometry; and acquiring information on Group A Streptococcus of emm type 1, based on the presence or absence, or magnitude of a peak in a first range of m/z of 10930 or more to 10945 or less in the mass spectrum.

The production and use of semiconducting nanopost arrays made by nanofabrication is described herein. These nanopost arrays (NAPA) provide improved laser ionization yields and controllable fragmentation with switching or modulation capabilities for mass spectrometric detection and identification of samples deposited on them.

Mass spectra acquired by imaging mass spectrometry (IMS), in particular MALDI imaging of tissue sections, are each normalized by one of: the p-norm of the mass spectrum transformed by applying an exclusion list, the p-norm of the mass spectrum transformed by square rooting the intensity values, the median of the mass spectrum, and the median absolute deviation of the noise level of the mass spectrum.