Capillary Gel Electrophoresis of Proteins: Past and Present Advances

Capillary gel electrophoresis (CGE) of proteins is a powerful analytical technique that has been used for several decades in the fields of biopharmaceuticals, biomedical, and food and agriculture. In a recent review article published in TrAC Trends in Analytical Chemistry, András Guttman from the University of Pannonia in Hungary, Seoul National University in South Korea, and University of Debrecen in Hungary provides a historical overview of CGE and highlights the recent advances and applications of the method (1).

DNA molecule double helix 3D rendering | Image Credit: © Matthieu Tuffet - stock.adobe.com

CGE is an analytical technique used to separate and characterize macromolecules such as proteins and nucleic acids based on their size and charge. It involves the use of a gel-filled capillary tube that acts as a separation medium. The sample is injected into the capillary and subjected to an electric field, which causes the macromolecules to migrate through the gel. On the other hand, sodium dodecyl sulfate CGE (SDS-CGE) involves the use of SDS to denature and uniformly charge proteins before CGE separation, allowing for more accurate size determination.

Proteins are important biomacromolecules that play a critical role in various biological processes. The use of monoclonal and multispecific antibodies, fusion proteins, antibody-drug conjugates, and nanobodies have become increasingly important drug candidates in the biopharmaceutical industry. High sensitivity and high throughput bioanalytical methods are required to analyze them.

CGE separates proteins based on their charge to hydrodynamic volume ratios, which are influenced by the reticulations of the sieving matrix. The most commonly used sieving matrices are hydrophilic linear polymers such as non-cross-linked polyacrylamide, polyethylene oxide, polyethylene glycol, dextran, and alkylated cellulose derivatives. The separation process in CGE can be fully automated because of the use of replaceable sieving matrices.

The review emphasizes the importance of eliminating the electroosmotic flow and preventing solute adsorption onto the inner capillary surface. This is usually achieved through the application of covalent or dynamic coatings. The article highlights the strengths and weaknesses of CGE and discusses the future potential of the technique.

In conclusion, CGE is a powerful analytical technique that has been used for several decades and has undergone significant advancements. The technique has found applications in various fields, including biopharmaceuticals, biomedical, and food and agriculture. With further advancements, CGE has the potential to become a widely used technique for the analysis of proteins in different areas of research.

Reference

(1) Hajba, L.; Jeong, S.; Chung, D. S.; Guttman, A.Capillary Gel Electrophoresis of Proteins: Historical overview and recent advances. TrAC - Trends Anal. Chem. 2023, 162, 117024. DOI: 10.1016/j.trac.2023.117024