Peptide Quantification
Peptide Quantification - Related Videos
08:57
Peptide and Protein Quantification Using Automated Immuno-MALDI (iMALDI)
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Cited by 13 •
2017
A protocol for the protein quantification in complex biological fluids using automated immuno-MALDI (iMALDI) technology is presented.
06:09
Quantification of Proteins Using Peptide Immunoaffinity Enrichment Coupled with Mass Spectrometry
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Cited by 37 •
2011
Stable Isotope Standards and Capture by Anti-Peptide Antibodies (SISCAPA) couples affinity enrichment of peptides with stable isotope dilution mass spectrometry (MRM-MS) to provide quantitative measurement of peptides as surrogates for their respective proteins. Here we describe the protocol using magnetic particles in a partially automated format.
05:43
A STAGE Tip Procedure for Desalting and Purification of Peptides
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2026
Source:Tia Rizakos1, Jennifer Geddes-McAlister11Molecular and Cellular Biology Department, University of Guelph.This video demonstrates peptide purification through the STAGE Tip procedure. A miniature column containing resin beads bonded to long hydrocarbon chains facilitates hydrophobic interaction-based purification. Upon loading a pre-digested peptide sample into the column, the peptide fragments bind to the resin beads, allowing impurities to pass through. An elution buffer that disrupts...
04:00
Immunoaffinity Based Extraction of Ubiquitinylated Peptides: A Technique to Selectively Extract Ubiquitin Tagged Peptides from Purified Peptide Fractions
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2023
This video describes a method to extract and purify ubiquitinylated peptides containing remnant di-glycine peptides from a complex peptide mixture. The presented method may help in identifying original ubiquitination sites in the protein.
03:21
Peptide Purification: An RP-HPLC-based Technique to Extract Peptides from Digested Protein Lysates
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2023
In this video, we demonstrate reversed-phase high-performance liquid chromatography to purify peptides from a digested protein lysate mixture. These purified peptides are then lyophilized and stored for downstream applications. Analysis of peptides can help understand the mechanics involved in cellular signaling and cancer.
FAQs
Ultraviolet-based measurements use absorbance contributed by aromatic residues within peptides. The resulting signal provides a basis for estimating concentration, but its usefulness depends on the peptide composition because different peptides may contain different amounts of these residues. This approach is therefore most informative when the sample’s composition is sufficiently characterized for absorbance to reflect peptide abundance.
Colorimetric approaches generate a measurable color when peptide bonds or particular side chains react with assay reagents. The intensity of that color is used to estimate the amount of peptide present. Because the reaction depends on peptide features and reagent response, the assay should be matched to the composition of the sample and the measurement goal.
Chromatographic separation followed by mass spectrometric detection quantifies peptides through signal intensity associated with the separated sample. This strategy is useful when the sample contains multiple peptide components and requires analytical information beyond a single bulk measurement. In biology, it can support peptide analysis connected to digestion studies and biomarker investigations.
Method selection depends on peptide composition, sample complexity, and the sensitivity required for the measurement. Ultraviolet absorbance, reagent-based color development, and chromatographic mass spectrometric detection rely on different measurable properties. Matching the method to these sample and experimental characteristics improves the accuracy and reproducibility of comparisons, solution preparation, and product assessment.
First, consider the peptide composition, sample complexity, and required sensitivity. Next, select an approach based on ultraviolet absorbance, reagent-driven color development, or chromatographic and mass spectrometric signal. Use the resulting concentration measurement to compare biological experiments or prepare standardized solutions, keeping the same measurement strategy across samples to support reproducible interpretation.
Measurements can evaluate whether purified or synthesized peptide preparations contain the expected amount of peptide and can support consistent preparation of solutions. These data provide a basis for quality control by making material quantities comparable across preparations. The selected assay should reflect the peptide’s composition and the complexity of the preparation being assessed.
Biological applications include studies of protein digestion, analysis of biomarkers, investigation of antimicrobial peptides, and quality control for synthetic or purified products. In each setting, concentration data help researchers compare samples or standardize experimental inputs. The analytical approach may differ according to whether the sample is simple, compositionally varied, or requires chromatographic and mass spectrometric detection.