Precursor mass and fragment. Medical search. Frequent questions

1] In a previous study, it was demonstrated that CID experiments on the [M + 103]+ adduct ions, using a quadruple ion-trap mass spectrometer, was effective for the differentiation of isomeric naturally-occurring phenols. (unica.it)
2] However, the fragmentation behaviour of the [M + 25]+ fragment ions was not investigated. (unica.it)
This study illustrates the effectiveness of CI (α-PVC) for isomer differentiation based on the CID mass spectra of the [M + 25]+ fragment ions. (unica.it)
Covers a method for matching a precursor ion with one or more related product ions using data sets obtained from sample injections including a precursor ion and product ions, normalizing these data sets in accordance with a single retention time for the precursor ion, and then establishing a predetermined retention time window with respect to this single retention time within which products ions are determined to be related to the precursor. (genomeweb.com)
Covers a method for analyzing chemicals by fractionating a complex sample into at least two portions, performing LC-MS on the samples, and associating precursor ions observed via LC-MS with corresponding polypeptides based on the intensity ratios in the different samples. (genomeweb.com)
System and method for grouping precursor and fragment ions using selected ion chromatograms. (genomeweb.com)
The tandem mass spectrometer ran in Multiple Reaction Monitoring (MRM) mode where the precursor ions fragmented with nitrogen gas in the collision cell at a defined electron voltage. (cdc.gov)
Based on this information .mol files were generated using Chemsketch software for the precursor and fragment ions of the standard and known impurities. (shimadzu.com)
The practice of simultaneous MS is frequently termed tandem mass spectrometry (MS/MS or MS 2 ) and refers to two or more reaction steps being performed on selected ions. (thermofisher.com)
In the first step of mass analysis, precursor ions are formed in the ion source and induced to fragment. (thermofisher.com)
Selection of both precursor and fragment ions, as well as their number during each step of the process, can vary depending on the goal of the analysis. (thermofisher.com)
Learn more about how mass analyzers separate, select and even fragment ions based on their distinct masses and charges. (thermofisher.com)
Relative partial ionization cross-sections (PICS) are derived for the formation of positively charged fragment ions, following electron ionization of H2S, CH3OH and CF3I. (bl.uk)
The 2D ion coincidence technique enables fragment ions formed by dissociative single, double, triple and quadruple ionization to be distinguished and quantified. (bl.uk)
Chimeric MS/MS spectra contain fragments from multiple precursor ions and therefore hinder compound identification in metabolomics. (cdc.gov)
The eluted peptides were analyzed using Orbitrap Fusion mass spectrometer operated in the data-dependent acquisition mode acquiring fragmentation spectra of the top 35 strongest ions. (mendeley.com)
After selecting the appropriate precursor ions, several MS n experiments could be performed during one introduction of the sample, with product ions obtained serving as parent ions for the next stage of fragmentation. (shimadzu-webapp.eu)

Due to the complex nature of peptide fragmentation in a mass spectrometer, derivative fragmentation patterns fall short of reproducing experimental mass spectra, especially relative intensities among distinct fragments. (wikipedia.org)
However, other precursors can fall into the fragmentation window for a given peptide, and the reporters released by these additional precursors can interfere with the reporters released by the target peptide, making quantitation unreliable in some cases. (genomeweb.com)
Observed mass spectrum and fragmentation pattern are showed in Figure 3. (shimadzu.com)
Accurate mass identification and MSMS fragmentation pattern of these 3 impurities were used to predict molecular formula with mass accuracy of about 1 ppm or less as shown in the Table 3 and Figure 5. (shimadzu.com)
The full MS scan was performed in Orbitrap in the range of 300-1400m/z at 120,000 resolutions (AGC 5e5, max IT 50ms) followed by rapid IonTrap HCD MS2 fragmentation (CE30%, AGC 5e4, max IT 30ms) at precursor isolation width of 3m/z. (mendeley.com)
MS n spectra with high mass accuracy offer im-proved reliability of signal assignment and structural analysis by fragmentation pathways. (shimadzu-webapp.eu)
The single-charged fragments resulting do not contain a mobile proton and may undergo fragmentation according to charge remote fragmentation mechanism. (shimadzu-webapp.eu)
The main objective of LYCCA is to uniquely characterize exotic nuclei by their mass, A , and charge, Z . The nuclei are secondary reaction products following Coulomb excitation, direct reactions, or fragmentation reactions of relativistic radioactive ion beams. (lu.se)

citation needed] One potential application of peptide spectral libraries is the identification of new, currently unknown mass spectra. (wikipedia.org)
Spectral libraries have been used in the small molecules mass spectra identification since the 1980s. (wikipedia.org)
the mass spectra corresponding to the fragments of peptide precursor is recorded. (wikipedia.org)
Tandem mass spectra contains specific information regarding the sequence of the peptide precursor, which can aid the identification of peptide/protein. (wikipedia.org)
Sequence database searching is widely used currently for mass spectra based protein identification. (wikipedia.org)
Such derivative patterns are used as templates to find a sufficiently close match within experimental mass spectra, which serves as the basis for peptide/protein identification. (wikipedia.org)
Second, by taking full advantage of all spectral features including relative fragment intensities, neutral losses from fragments and various additional specific fragments, the process of spectra searching will be more specific, and it will generally provide better discrimination between true and false matches. (wikipedia.org)
Fortunately, more and more high-quality mass spectra are being acquired by the collective contribution of the scientific community, which will continuously expand the coverage of peptide spectral library. (wikipedia.org)
Computer-aided identification of compounds by comparison of mass spectra. (wikipedia.org)
Here we describe a program called Preview that analyzes a set of mass spectra for mass errors, digestion specificity, and known and unknown modifications, thereby facilitating parameter selection. (parc.com)
Precise analysis of the resulting fragments requires high-resolution spectra which can only be guaranteed with IT-TOF instruments. (shimadzu-webapp.eu)

Subsequently, one or more chromatographic separations are applied to resolve resulting peptides, which are then ionized and analyzed in a mass spectrometer. (wikipedia.org)
The eluates were ionized at 70eV in the electron source of the mass spectrometer. (cdc.gov)
This study has been carried out for structural elucidation of paracetamol and its related impurities followed by quantitation of representative impurities using LCMS-9030 (Shimadzu Corporation, Japan), a Quadrupole Time of flight liquid chromatograph mass spectrometer. (shimadzu.com)
The LCMS-9030 quadrupole time-of-flight (Q-TOF) mass spectrometer integrates the world's fastest and most sensitive quadrupole technology with TOF architecture. (shimadzu.com)
Atoms and molecules must first be ionized before they can be accelerated through the mass spectrometer and detected. (thermofisher.com)
The heart of the mass spectrometer is its mass analyzer. (thermofisher.com)
Samples must be ionized (or charged) before they can be manipulated by electric and magnetic fields within the mass spectrometer. (thermofisher.com)
Firstly, using a time-of-flight mass spectrometer coupled with a 2D ion coincidence technique, studies of the electron ionization of a number of small gas-phase molecules are presented. (bl.uk)
Finally, studies of I2+ collisions with OCS, carried out using a crossed ion beam experiment with a time-of-flight mass spectrometer, are presented. (bl.uk)
The mass spectrometer enables analysis of thousands of samples without loss in performance, delivers accurate and reproducible quantitation of thousands of proteins. (thermofisher.com)
By combining the proven performance of the Orbitrap mass analyzer with the speed (200 Hz) and sensitivity of the novel Astral mass analyzer, the Orbitrap Astral mass spectrometer enables faster throughput and deeper proteome coverage. (thermofisher.com)

The current practice of interpreting immunoreactivities seen with commonly used antibodies as "Aβ" without controlling for the other fragments misleads the entire amyloid based research approach. (j-alz.com)
Mass spectrometry-based proteomics is an alternative approach that allows efficient quantification of thousands of amyloid plaque proteins simultaneously. (researchsquare.com)

Tandem mass spectrometry, which is an ideal match for the large-scale protein identification and quantification in complex biological systems. (wikipedia.org)
The mass of the predicted mature protein of Bothrops protease A, a trypsin-like serine peptidase, is 25.4 kDa. (springer.com)
The Thermo Scientific FAIMS Pro Duo interface enhances precursor selectivity, improving qualitative and quantitative results for most peptide and protein applications while reducing time-consuming sample preparation steps. (thermofisher.com)
This protein is an aminopeptidase, which is an enzyme that cuts (cleaves) other proteins into smaller fragments called peptides. (medlineplus.gov)

Weathering, on the other hand, is the process of breaking down rocks into smaller fragments, which is a precursor to erosion. (proprofs.com)

Covers a method of pulsed multiple-reaction monitoring mass spectrometry that uses pulsed ion injection mode to reduce background and increase signal to allow for quantitation of proteins and peptides at attomole levels. (genomeweb.com)

Covers a method of acquiring information on a target by ionizing the target and collecting information on its mass via time-of-flight mass spectrometry. (genomeweb.com)
Cell proteins were analysed with 2-dimensional electrophoresis and differentially expressed proteins were identified by matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry. (who.int)

We determined urinary OH-PAHs concentration using ultrahigh performance liquid chromatography-tandem mass spectrometry, and analyzed its association with occupational stress using multiple linear regression, covariate balancing generalized propensity score (CBGPS), and Bayesian kernel machine regression (BKMR). (bvsalud.org)
A candidate RMP (cRMP) was developed for the measurement of total E2 in serum using liquid chromatography-tandem mass spectrometry (LC-MS/MS) without derivatization. (cdc.gov)
and one uses liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology. (cdc.gov)

This method was based on headspace solid phase microextraction coupled to gas chromatography-tandem mass spectrometry (HS-SPME-GC-MS/MS) (Silva et. (cdc.gov)
Isobaric labeling uses stable isotope tags attached to peptides of interest to enable relative or absolute quantitation of proteins via tandem mass spectrometry. (genomeweb.com)
These reagents, which are sold as tandem mass tags, or TMT, by Thermo Fisher Scientific through a licensing agreement with Proteome Sciences, and as isobaric tags for relative and absolute quantitation, or iTRAQ, by AB Sciex, enable researchers to multiplex up to eight samples. (genomeweb.com)
Database search programs for peptide identification by tandem mass spectrometry ask their users to set various parameters, including precursor and fragment mass tolerances, digestion specificity, and allowed types of modifications. (parc.com)
Bern, M. W. Preview: a program for surveying shotgun proteomics tandem mass spectrometry data. (parc.com)
The possibility to create a database from predicted caspase cleavage products for the whole genome could significantly aid in identifying novel caspase targets from tandem mass spectrometry based proteomic experiments. (biomedcentral.com)
A database was constructed with the developed tool, and it was used to identify caspase target proteins from tandem mass spectrometry data from two different proteomic experiments. (biomedcentral.com)
To gain a better understanding of the molecular mechanisms of rice bakanae disease resistance, we employed a 6-plex tandem mass tag approach for relative quantitative proteomic comparison of infected and uninfected rice seedlings 7 days post-inoculation with two genotypes: the resistant genotype 93-11 and the susceptible genotype Nipponbare. (biomedcentral.com)
Tandem mass spectrometry is a powerful tool in proteomic re-search. (shimadzu-webapp.eu)

SILAC - or stable isotope labeling by amino acids in cell culture - uses the incorporation of amino acids containing different isotopes to label proteomic samples for quantitative mass spec analysis. (genomeweb.com)

Because mass spec resolution isn't infinite, however, the UW-Madison team maxed out at six-plex analysis, running the experiment at 240,000 resolution on a Thermo Fisher Scientific Orbitrap Elite. (genomeweb.com)

Mass spectrometry (MS) is a powerful technique for the characterization of isomeric compounds. (unica.it)
In particularly, we focused our attention on certain class of low mass isomeric compounds where conventional EI-MS (/MS) does not work successfully. (unica.it)
Only those compounds which give that specific fragment ion are detected. (golembiewskilukasz.pl)

University of Wisconsin-Madison researchers have developed a new labeling approach that could enable significantly higher multiplexing in mass spec proteomics experiments. (genomeweb.com)
Last year, two groups - one led by Harvard University researcher Steven Gygi and another by researchers from chemical proteomics firm Cellzome (since acquired by GlaxoSmithKline) - applied this phenomenon to isobaric tagging, swapping the tags' 12 C atoms for 13 C atoms and 15 N for 14 N to produce a 6-mDa mass shift that upped the reagents' multiplexing capability from six-plex to eight-plex. (genomeweb.com)

The different approaches to sample labeling and mass spectrometry analysis. (thermofisher.com)
We investigated the entire set of proteins modulated by BAG3 silencing in the human anaplastic thyroid 8505C cancer cells by using the Stable-Isotope Labeling by Amino acids in Cell culture strategy combined with mass spectrometry analysis. (oncotarget.com)

Using different isotopes of carbon, hydrogen, nitrogen, and oxygen, the researchers worked out 39 distinct isotopologues for lysine spanning a mass range of roughly 39 mDa and separated by 1 mDa each. (genomeweb.com)

Aβ-type fragments of any sequence length in any aggregation state in relation to AD have not been systematically investigated in humans. (j-alz.com)
Peak at m/z 209 after MS 3 experiment corresponded to the internal fragment of peptide sequence. (shimadzu-webapp.eu)

however, a detailed investigation of Aβ-related AβPP proteolytic fragments in experimental settings reveals a multitude of associated soluble peptides [19] few of which have been systematically investigated with respect to AD. (j-alz.com)
Orbitrap Ascend Mass Spectrometer's new innovations deliver ultimate flexibility in experimental scope, accelerating your path to new, impactful results, to drive your science beyond today's discovery. (thermofisher.com)

Estimation of ion cyclotron resonance parameters in fourier transform mass spectrometry. (genomeweb.com)
Covers a method and system for estimating the ion cyclotron resonance parameters in Fourier-transform mass spectrometry. (genomeweb.com)

Given infinite mass spec resolution, Coon told ProteoMonitor , researchers could distinguish between each of these 39, allowing them to multiplex up to 39 samples in a single experiment. (genomeweb.com)
With isobaric tagging, researchers isolate a precursor peptide and fragment it with MS2, causing the tag's reporter to fall off, with the proportion of these reporter signals correlating to the proportions of a given peptide in the tagged sample. (genomeweb.com)

This is because mass spectrometers separate particles by calculating their different mass-to-charge ratios (m/z). (thermofisher.com)
Different analyzers are also combined in hybrid and tribrid mass spectrometers. (thermofisher.com)
Mass spectrometry is an analysis method that can be performed once using a single analyzer, or it can be performed in tandem between different mass analyzers (such as those found in hybrid or tribrid mass spectrometers). (thermofisher.com)
The general operation of mass spectrometers, including hybrid and tribrid mass spectrometers. (thermofisher.com)
During label-free relative quantitation workflows, digested peptides are separated by LC prior to MS. RP separation on Thermo Scientific low-flow systems integrates well with label-free quantitation workflows and combines seamlessly with Thermo Scientific Orbitrap mass spectrometers. (thermofisher.com)

However, because quantitation is done at the MS2 level, precursor interference can be a problem. (genomeweb.com)

Structural elucidation for pharmaceutical impurities involves multitude of analytical techniques, such as NMR, mass spectrometry, infrared spectroscopy etc. (shimadzu.com)
The last two features have made the structural characterization of the new peptides by mass spectrometry a real analytical challenge. (springer.com)
Precursor ion Intelligent structural and screening scans. (golembiewskilukasz.pl)

Learn how Orbitrap technology has revolutionized mass spectrometry for over a decade. (thermofisher.com)

These functions are coordinated by the following components: the ion source, mass analyzer, detector and software. (thermofisher.com)

While the relative PICS quantify the overall yield of each fragment ion, the precursor specific relative PICS quantify the contribution from single, double, triple and quadruple ionization to the relative yields of each fragment ion. (bl.uk)

A fifth difficulty arises when assigning functions to specific fragments from the AβPP proteolytic system. (j-alz.com)
This information also allows precursor specific relative PICS to be determined. (bl.uk)

The software package MEGA version 4.0 ( 11 ) was used to construct an alignment of a 283-nt fragment of the GPC gene nucleotide sequences and predicted amino acid sequences, and for phylogenetic analysis with the neighbor-joining method (p distance model), with bootstrap support based on 1,000 pseudoreplicates. (cdc.gov)

Modern tandem MS instruments combine features of fast duty cycle, exquisite sensitivity, and unprecedented mass accuracy. (wikipedia.org)

Some fragments are known to cross-react with commonly used antibodies introducing confounding in interpretations of immunoassays and immunohistochemistry for Aβ, of which the perhaps most concerning is the confounding by P3-40 and P3-42 (derived from the alternate α-pathway of AβPP cleavage) in cerebrospinal fluid based biomarkers relating to C-terminal Aβ and in neuropathological diagnostic protocols using the anti-Aβ antibody 4G8 [20]. (j-alz.com)
Serum samples were separated by centrifugation (10,000 rpm, 10 min) and tested for LCMV antibody by using the manufacturer's protocol for commercial indirect fluorescent antibody assay slides (Charles River Laboratories, Wilmington, MA, USA). (cdc.gov)

Some examples of mass analyzers include quadrupoles , triple quadrupoles , ion traps , Orbitraps, Fourier transform, magnetic sectors and time-of-flight (TOF) instruments. (thermofisher.com)

Access our extensive collection of mass spectrometry workflows, scientific applications, technical handbooks, webinars and more. (thermofisher.com)

The enhanced reactivity profile of 4G8 when compared to both 6E10 and 6F3D illustrated in Alafuzoff et al [21] may be due to its reactivity with P3 type fragments in addition to Aβ- type fragments. (j-alz.com)

A radioactive ion beam (RIB) enters the focal plane experiment area from the left (see also the photograph of PRESPEC ), along with A - und Z -identification by detectors related to the roughly 80 meter long GSI Fragment Separator (not shown). (lu.se)

The observed mass to charge ratio (m/z) and their respective mass accuracy are given in Table 2. (shimadzu.com)
Mass accuracy for all the analyzed components was found to be less than 2 ppm, through out the experiment. (shimadzu.com)
UFgrating, iRefTOF and UF-FlightTube resulted in mass accuracy values less than 2 ppm through out the analysis. (shimadzu.com)
Why is high mass accuracy important? (thermofisher.com)
The IT-TOF instrument provides high resolution and accuracy for all MS and MS n modes as well as mass stability and excellent resolution for LC-MS analysis. (shimadzu-webapp.eu)

Mass spectrometry has four essential functions, which are ionization, separation (filtering), detection and analysis. (thermofisher.com)
We combined High-Resolution Mass Spectrometry and transcriptome analysis to study the OM composition of the axial skeleton and the sclerites. (biomedcentral.com)

Most investigations focus on Aβ alone without taking the complexity of the AβPP proteolytic system into account however, this neglects the contributions from full length AβPP and other proteolytic fragments derived from AβPP including the N-terminal sAPPα released following α-cleavage and sAPPβ released following β-cleavage. (j-alz.com)
Symptoms and Signs Platelets are circulating cell fragments that function in the clotting system. (msdmanuals.com)

Moreover, Preview optionally recalibrates mass over charge measurements, leading to further improvement in identification results. (parc.com)
Aplastic anemia is a disorder of the hematopoietic stem cell that results in a loss of blood cell precursors, hypoplasia or aplasia of bone marrow, and cytopenias in two or more cell lines (red blood cells, white blood cells, and/or platelets). (msdmanuals.com)
Pure Red Blood Cell Aplasia Acquired pure red blood cell aplasia is a disorder of erythroid precursors that results in an isolated normocytic anemia. (msdmanuals.com)

Rather, mass photometry, crosslinking mass spectrometry, single molecule TIRF microscopy and biochemical assays identify inter-holoenzyme phosphorylation (IHP) as the mechanism for spreading phosphorylation. (elifesciences.org)

A selection of samples found negative by the GPC PCR were subsequently retested by PCR targeted at a fragment of the nucleoprotein (N) gene ( 8 ), by using primers to sequences common to the Old World arenaviruses. (cdc.gov)

The differences between commonly used mass analyzers. (thermofisher.com)

Digested peptides are labeled with tags that fragment during MS2 to produce signals corresponding to the amount of peptide present in a sample. (genomeweb.com)

Here, we used mass spectrometry (MS)-based methods to determine and quantify, in a time-dependent manner, early molecular events triggered following TCR stimulation with peptides of varying affinities. (nature.com)
The molecular mass of classical mamba toxins is in the range of 7 to 25 kDa. (springer.com)
The ER aminopeptidase, ERAP1, trims precursors to lengths of MHC class I peptides by a 'molecular ruler' mechanism. (medlineplus.gov)

The fragments of Pangaea that began to separate were the precursors of the continents we know today. (podium.school)

Regarding only snake venoms, several high mass enzymes have been found to be glycosylated. (springer.com)

Anatomy3

Organisms1

Chemicals and Drugs20

Analytical, Diagnostic and Therapeutic Techniques and Equipment12

Phenomena and Processes16

Information Science3

Health Care1

Ions17

Fragmentation8

Spectra11

Spectrometer11

Amyloid2

Protein4

Smaller fragments1

Monitoring mass spectrometry1

Time-of-flight ma2

Liquid chromatography-tandem mass spectro3

Tandem mass9

Quantitative1

Thermo Fisher Sci1

Compounds3

Proteomics2

Spectrometry analysis2

Distinct1

Sequence2

Experimental2

Parameters2

Researchers2

Spectrometers5

Quantitation1

Structural3

Orbitrap1

Analyzer1

Quadruple1

Specific2

Amino1

Sensitivity1

Antibody2

Fourier1

Workflows1

Type1

Roughly1

Accuracy5

Analysis2

System2

Results3

Single1

Selection1

Commonly1

Sample1

Molecular3

Separate1

High1