Superporous agarose, a new material for chromatography

This paper reports on a new type of spherical agarose chromatography particles characterized by two sets of pores, normal diffusion pores, characteristic of all agarose materials and very wide pores, so-called superpores or flow pores. These superpores allow part of the chromatographic flow to pass through each individual particle, which gives improved mass transfer, especially in situations where diffusion is the limiting factor for the overall performance of a chromatographic separation. The particles were prepared by a double emulsification procedure. Observations under a microscope and size-exclusion chromatography were used in order to demonstrate pore flow. The chromatographic behaviour of the new particles was as efficient as that of homogeneous particles which were several times smaller. The agarose particles were derivatized with polyethyleneimine and used for an ion-exchange chromatographic separation of three model proteins. As expected from a perfusion material, the superporous beads resolved the protein mixture more efficiently than homogeneous beads of the same size.