Immunochemical characteristics and preparative application of agarose-based immunosorbents

The physical and chemical properties of immunosorbents prepared from Sepharose 4B have been studied, with the objective of improving their utility in preparative applications. The most significant factors influencing efficient use of these immobilized reagents are loss of immunochemical reactivity with increasing protein substitution and the restrictions imposed by the porous nature of the support. Similar effects are observable with controlled-pore glass matrices, but they are of less significance when solid, nonporous supports are used. Considerable improvements in operational efficiencies have been obtained by limiting the amount of protein immobilization and restricting reaction to the more accessible surface regions of the porous supports. Improved operating protocols based on these principles have been adapted to automated chromatographic systems, resulting in a fourfold increase in productive capacity. With the addition of the continuous dialysis and concentration system described here, routine daily production of gram quantities of specific antibodies from antisera becomes possible. Similarly, with a knowledge of the basic characteristics of these immunosorbents, it has been possible to increase greatly the efficiency of small-scale separations and purifications of immunological reagents from limited sources. The general approach toward the practical exploitation of immunosorbents for preparative applications is discussed in the context of these findings.