Related Experiment Video
Updated: Aug 10, 2026

Capillary Electrophoresis to Monitor Peptide Grafting onto Chitosan Films in Real Time
Published on: October 26, 2016
Quantitatively investigating monomethoxypolyethylene glycol modification of protein by capillary electrophoresis
1State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100080, PR China. weijun@itsa.ucsf.edu
Abstract:
Capillary electrophoresis (CE) was applied to study quantitatively protein modification with succinimidyl succinate-activated monomethoxypolyethylene glycol (MPEG-SS). The heterogeneous distribution of modified proteins and the average modification degree were determined by CE, and the latter met with the results from 2,4,6-trinitrobenzenesulfonic acid (TNBS) spectrometric assay. It was found that the optimal buffer pH for the modification was between pH 7.4 and 8.4, and the modification degree decreased when the modified sample was preserved in high pH solutions. The protein fractions attached with different number of polyethylene glycols (PEGs) were monitored along the process of protein modification. CE was proved to be efficient to evaluate quantitatively several factors of the protein modification, including the modifier/protein molar ratio, the stability of conjugates in different pH environments, and the time course of modification process.
Related Concept Videos
SDS-PAGE
A variation of gel electrophoresis, termed polyacrylamide gel electrophoresis (PAGE), is commonly used for separating proteins according to their molecular size by passing them through a polyacrylamide gel. Because of the varying charges associated with amino acid side chains, PAGE can be used to separate intact proteins...
Two-dimensional Gel Electrophoresis
The first dimension separation uses the isoelectric focusing or IEF technique performed on immobilized pH gradient (IPG) strips that separate proteins according to their isoelectric points.
Biological samples, such as cells...
Electrophoresis: Overview
There...
Capillary Electrophoresis: Applications
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...

