Immunoadsorption is an application of affinity chromatography, as a therapeutic method to specifically deplete
biological fluids such as blood plasma from
proteins in excess, or to extract a biomolecule from a
complex mixture. However, the leakage of small amounts of
antibodies covalently immobilized on the support hampers the practical use of this method. In fact, these released
antibodies contaminate the purified
proteins or depleted media and, when they are of animal nature, they may lead to immunization of patients, or cause an
anaphylactic shock when a clinical use is concerned. It is therefore of prime importance that the
immunoadsorbents exhibit a satisfactory stability over the whole range of chemical and biochemical conditions involved during their clinical handling. To determine optimal conditions for the preparation of stable
immunoadsorbents designed to remove selectively
Low Density Lipoproteins (LDLs) from the plasma of patients affected by
familial hypercholesterolemia, various
immunoadsorbents were prepared by covalent immobilization of goat anti-
apolipoprotein B polyclonal
antibodies on different supports (
Sepharose CL-4B,
Sepharose 6 Fast Flow, Sphérodex and Fractogel) previously activated by various chemical
reagents (
cyanogen bromide,
divinyl sulphone,
tresyl chloride and
trichloro-s-triazine). Their adsorption capacity, specificity, stability and the amount of
immobilized antibodies were compared in terms of the activation method and the support used. It turns out that the
immunoadsorbents prepared with
Sepharose 6 Fast Flow lead to optimal yield of coupling, adsorption capacity, and an excellent stability at neutral pH. TC-activated-Fractogel turns out as well to afford an excellent coupling yield, a good adsorption capacity and an optimal stability in the whole pH range tested.