Since several years matrix-bound biologically active substances are widely used in biosciences, biotechnology and medicine. We are presenting a simple and inexpensive activation procedure for support materials which allows stable binding of C1q and DNA. We could not found a remarkable leakage of the bound ligands. In connection with the good biocompatibility of our procedure, both are important for the application in extracorporeal immunoadsorption. The method is technologically simple and represents an alternative to the activation methods applied so far.