This unit describes the derivatization of solid support media, particularly glass and polypropylene, with a linker system by an iterative process that forms a dendrimeric structure, thereby increasing stepwise the loading capacity of the surface. The procedure permits the production of various types of linkers whose characteristics can be tailored to the requirements of the eventual applications. The specific modifications described here are used either for attaching prefabricated DNA oligonucleotides, PCR products, and peptide nucleic acid (PNA) oligomers, or for in situ synthesis of DNA microarrays.