ElectrophoresisElectrophoretic methods have been applied to protein research for more than eighty years and allow separating proteins according to different physicochemical parameters such as charge or size. The proteins can be visualized after separation by many staining techniques, such as DIGE, silver stain, colloidal Coomassie etc.

The gel images are usually digitized using a scanner and the evaluated using dedicated software packages.

Protagen Protein Services GmbH offers a portfolio of electrophoretic separations, which can be tailored to the need of each individual project.


SDS-PAGE separated the protein in one dimension according to their apparent molecular weight. The molecular weight of the protein is then determined relative to a molecular weight marker. Reducing and non-reducing SDS-PAGE can be used to detect disulfide-linked oligomers or subunits.


IEF is used to separate proteins according to their net charge. This method is very powerful e.g. in detecting proteins with sialic acid variants or deamidated Aparagine.


In 2D PAGE, the sample is separated in two dimensions, first according to the pI of the protein and then according to the molecular weight. This two-dimensional separation results in gels with a very high resolution of protein spots making it an ideal tool for the study of complex protein mixtures (proteome studies) and impurity analysis.

Western Blotting

Western Blotting can be used in conjunction with the electrophoretic separations listed above to prove the identity of a protein by detection with a specific antibody. In combination with a polyclonal antibody e.g. raised against a cell lysate, western blotting can be used to assess the specificity of HCP-ELISAs.

The sample is dissolved in a suitable loading buffer, which typically contains denaturants, chaotropes and detergents. The choice of loading buffer must be compatible with the desired gel system. The sample is then separated by migration of the charged protein/detergent complexes in an electric field.

Mass spectrometry can be used to identify protein spots of interest in all of the 1D or 2D gels.

Electrophoretic patterns are required by ICH Q6B for the analysis of biopharmaceuticals.

Your contact for Electrophores at Protagen Protein Services GmbH

burkhard fleckenstein

Dr. Burkhard Fleckenstein

Director Operations 
Our business development team will be happy to assist you with your project.

Phone: +49 7131 74 50 40
Email: salesproteinservices@ProtagenProteinServices.com