Isolation of proteins from crude mixtures with silica and silica-based adsorbents.

Silica and silica-based adsorbents have been used to isolate specific proteins from crude mixtures. Acid-activated Nugel silica and Nugel SP-Silica were used to extract human immune interferon from the conditioned medium of mixed lymphocyte cultures. Human interleukin-2 was extracted from the conditioned medium of Jurkat cells with LiChroprep RP-8. In each case, batch absorption was accomplished by gentle stirring in a microcarrier vessel. The adsorbate was collected by sedimentation, and either batch-eluted or packed into a column for gradient elution. A high degree of concentration and purification was achieved with a high recovery of biological activity.