Sepharose

Sepharose is a tradename for a crosslinked, beaded-form of agarose (a polysaccharide polymer material extracted from seaweed). It is commonly used in affinity chromatography as the matrix. Protein A-agarose chromatography provides a simple and efficient method for purifying antibodies, streptavidin-agarose is used to purify biotin-labeled molecules, etc.

Sepharose/agarose, combined with some form of activation chemistry, is also used to immobilize enzymes, antibodies and other proteins and peptides through covalent attachment to the resin. [http://www.lsbu.ac.uk/biology/enztech/immethod.html] Common activation chemistries include cyanogen bromide (CNBr) activation and reductive amination of aldehydes to attach proteins to the agarose resin through lysine side chains. Iodoacetyl functional groups can be added to selectively bind cysteine side chains and this method is often used to immobilize peptides.