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Updated: Jun 23, 2026

Electrophoretic Separation of Proteins
Published on: June 12, 2008
Efficient electroblotting of very large proteins using a vertical agarose electrophoresis system
Marion L Greaser1, Chad M Warren
1University of Wisconsin-Madison, 1805 Linden Drive, Madison, WI, 53706, USA. mgreaser@ansci.wisc.edu
Abstract:
Very large proteins (subunit sizes >200 kDa) are difficult to electrophoretically separate, and they are also challenging to analyze by western blotting because of their incomplete transfer out of polyacrylamide gels. An SDS vertical agarose gel system has been developed that has vastly improved resolving power for very large proteins. The large pores of the agarose also allow full transfer of proteins as large as titin (Mr =3,000-3,700 kDa) onto blots. Inclusion of a reducing agent in the upper reservoir buffer and transfer buffer has been found to be a key technical procedure in blotting large proteins.
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