C18 Desalting
C18 Desalting - Related Videos
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...
11:02
Complete Workflow for Analysis of Histone Post-translational Modifications Using Bottom-up Mass Spectrometry: From Histone Extraction to Data Analysis
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Cited by 227 •
2016
This protocol outlines a fully integrated workflow for characterizing histone post-translational modifications using mass spectrometry (MS). The workflow includes histone purification from cell cultures or tissues, histone derivatization and digestion, MS analysis using nano-flow liquid chromatography and instructions for data analysis. The protocol is designed for completion within 2 - 3 days.
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.
11:37
Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism
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Cited by 5 •
2017
This article provides a detailed procedure on the solid-phase synthesis, purification, and characterization of dodecamers of RNA modified at the C2'-O-position. UV-vis and circular dichroism photometric analyses are used to quantify and characterize structural aspects, i.e., single-strands or double-strands.
09:26
Species Determination and Quantitation in Mixtures Using MRM Mass Spectrometry of Peptides Applied to Meat Authentication
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Cited by 4 •
2016
We present a protocol for identifying and quantifying the components in mixtures of species possessing similar proteins. Mass spectrometry detects peptides for identification, and gives relative quantitation by ratios of peak areas. As a tool food for fraud detection, the method can detect 1% horse in beef.
FAQs
The separation depends on the interaction between peptide hydrophobic regions and the C18 silica surface. These hydrophobic chains retain peptides and other analytes, whereas salts and other small, polar contaminants remain associated with the aqueous phase and are removed during washing. This difference in chemical behavior allows the target sample to remain on the material while unwanted components are discarded.
Aqueous washes selectively carry away salts and other small, polar contaminants while the retained peptides remain associated with the hydrophobic C18 surface. Removing these substances before elution reduces the burden of interfering components in the recovered sample. The resulting cleanup is especially important when the sample will undergo chromatographic or mass spectrometric analysis.
By removing salts and concentrating the retained sample, C18 desalting creates conditions that support more effective ionization and cleaner spectral measurements. Improved spectral quality can make peptide and protein signals easier to interpret, supporting reliable protein identification and quantitative comparisons. This benefit connects the preparation step directly to the quality of downstream analytical results.
A typical workflow retains the peptide or protein solution on reversed-phase C18 silica, washes the material with an aqueous solution to remove salts and other small polar contaminants, and then elutes the retained sample with an organic solvent. Acidified acetonitrile is often used for elution. This sequence both cleans and concentrates the material for subsequent analysis.
Reversed-phase C18 silica provides the hydrophobic surface that retains peptides and other analytes. Aqueous solutions serve as the washing environment, allowing salts and small polar contaminants to be carried away. An organic solvent, often acidified acetonitrile, releases the retained material during elution. Together, these components create the cleanup and concentration sequence.
In cancer research, the method is useful before proteomic measurements, biomarker discovery, and analysis of tumor-associated peptides. Cleaner, more concentrated samples can support protein identification, quantitative comparisons, and downstream characterization of cancer-related molecular changes. Its value lies in strengthening the analytical quality of samples used to investigate molecular differences associated with tumors.