Method for the separation of protein-bound substances from a protein-containing liquid by dialysis

A process of separating substances bound to a first protein in a first liquid by means of a semipermeable membrane separating the first liquid from a second liquid, the process comprising the steps of:

• a) impregnating the membrane by passing a solution along both sides of the membrane, the solution containing the first protein, which first protein has an acceptor function for the substances to be separated and an affinity for the membrane, for a period of time sufficient to permit penetration and adsorption of the first protein on both sides of the membrane;
• and
• b) passing the first liquid and the second liquid on each side of said semipermeable membrane, the second liquid containing the first protein in free form, wherein the membrane contains (i) a first structure facing the first liquid and having tunnels with a length of 0.01 to 0.1 micrometer and a diameter that permits passage of the substances to be separated but excludes passage of the first protein and (ii) a port- and adsorption structure facing the second liquid that permits the second liquid and the first protein therein to pass into and out of the port- and adsorption structure, whereby the substances bound to the first protein in the first liquid are separated from the first protein and passed through the membrane to the first protein in the second liquid.