Abstract: There are disclosed a method for determining binding constants between a substance or a substance mixture and a target, and a kit for carrying out the method according to the invention. The binding constants of the substance for the targets are determined by shifting the binding equilibrium. The concentrations of the immobilised and the dissolved target are varied and the affinities with the targets are determined by shifting the binding equilibria in the individual batches.

Abstract: There are disclosed a method for determining binding constants between a substance or a substance mixture and a target, and a kit for carrying out the method according to the invention. The binding constants of the substance for the targets are determined by shifting the binding equilibrium. The concentrations of the immobilised and the dissolved target, are varied and the affinities with the targets are determined by shifting the binding equilibria in the individual batches.

Abstract: A method includes incubating at least a first and a second sample of the substance or of the substance mixture with the target immobilized on a solid carrier. Incubation is in each case effected in a sample container. The first and the second sample are incubated with different amounts of the target, whereas all sample containers include the same amount of buffer solution during incubation. After incubation, the solid carrier is separated from the buffer solutions together with the target immobilized thereon as well as, if applicable, substance bound thereon. The concentration of the substance or of the substance mixture is then measured in the respective supernatant.

Abstract: A method determines or estimates the absorption and partition of substances into brain tissue and parameters derivable therefrom, such as the permeability of substances through the blood-brain barrier and also, more particularly, the proportion of substances freely available in the brain. The partition coefficient of the corresponding substance between an aqueous phase and the lipid phase is determined with the help of lipid membranes which are preferably contained in a test kit and immobilized on a solid body as a carrier material. The partition coefficient can be subsequently used as a parameter in a QSAR model to determine the blood-brain partition coefficient.