Q-exactive Ms
Q-exactive Ms - Related Videos
01:08
Fisher's Exact Test
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2025
Fisher's exact test is a statistical significance test widely used to analyze 2x2 contingency tables, particularly in situations where sample sizes are small. Unlike the chi-squared test, which approximates P-values and assumes minimum expected frequencies of at least five in each cell, Fisher's exact test calculates the exact probability (P-value) of observing the data or more extreme results under the null hypothesis. This feature makes it especially valuable when the assumptions of the...
01:27
State Function, Exact and Inexact Differentials
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2026
A state function is a thermodynamic property that depends solely on the current state of a system, irrespective of its history or how it arrived at that state. These functions are represented by capital letters, such as U, H, and S, which stand for internal energy, enthalpy, and entropy, respectively.For instance, the value of internal energy depends on the system's state variables and remains unaffected by the process path. This means that whether the system underwent a linear process or a...
11:16
Discovering Protein Interactions and Characterizing Protein Function Using HaloTag Technology
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Cited by 11 •
2014
HaloTag technology is a multifunctional technology which has shown significant success in isolation of both small and large protein complexes from mammalian cells. Here we highlight the advantages of this technology compared to existing alternatives and demonstrate its utility to study numerous aspects of protein function inside eukaryotic cells.
10:22
Basophil Activation Test for Investigation of IgE-Mediated Mechanisms in Drug Hypersensitivity
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Cited by 14 •
2011
Basophil activation test is a potent tool for the detection of IgE-dependent allergies in vitro. Here, an optimized protocol for basophil activation test is used to investigate drug hypersensitivity. A method for the efficient production of covalent drug-protein conjugates and their physicochemical characterization is described.
07:28
Transfection, Selection, and Colony-picking of Human Induced Pluripotent Stem Cells TALEN-targeted with a GFP Gene into the AAVS1 Safe Harbor
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Cited by 12 •
2015
TALEN-mediated gene editing at the safe harbor AAVS1 locus enables high-efficiency transgene addition in human iPSCs. This protocol describes the procedures for preparing iPSCs for TALEN and donor vector delivery, transfecting iPSCs, and selecting and isolating iPSC clones to achieve targeted integration of a GFP gene to generate reporter lines.
FAQs
The quadrupole narrows the ion population by selecting precursor ions before analysis of their fragments. Selected precursors can undergo higher-energy collisional dissociation, producing fragment ions that retain structural information about the original molecule. Measuring these fragments in the Orbitrap adds precise mass information, strengthening identification of peptides, proteins, lipids, and other biomolecules in complex biological samples.
High resolution helps distinguish ions with closely related mass-to-charge ratios, while high mass accuracy improves confidence in assigning detected signals to specific biomolecules. Together, these properties make the resulting measurements more informative than signal intensity alone. In biological studies, they support clearer interpretation of complex molecular profiles and more reliable characterization of peptides, proteins, and small molecules.
Targeted ion selection focuses measurement on precursor ions of interest, whereas full-scan analysis captures a broader view of the ions present in a sample. Using both approaches connects detailed examination of selected molecules with comprehensive molecular profiling. This combination can reveal known biomolecules while also supporting discovery of changes in the wider composition of a biological sample.
The workflow begins by introducing ions from the biological sample into the instrument and selecting precursor ions with the quadrupole. Selected ions may then be fragmented by higher-energy collisional dissociation. The resulting precursor and fragment ions enter the Orbitrap for high-resolution measurement, generating mass and fragmentation information that can be used for molecular identification and quantification.
Q Exactive MS is applied across proteomics, metabolomics, and lipidomics. These fields use its measurements to investigate peptides and proteins, small molecules, and lipids within biological samples. Because the platform combines molecular mass information with fragmentation data, it can support studies that seek to characterize biomolecules and compare the molecular composition of different biological conditions.
Measurements from this platform can reveal changes in the molecular content of cells by identifying and quantifying biomolecules in complex samples. Fragmentation data adds evidence for molecular assignments, while full-scan measurements provide broader compositional coverage. Interpreting these changes helps connect altered profiles of peptides, proteins, lipids, or small molecules with cellular composition and function.