The aim of this project was to investigate the suitability of DNA block copolymer aggregates to take part in catalytic reactions. DNA block copolymer (DBC) aggregates are composed of hybrids that contain a nucleic acid segment and a hydrophobic polymer. Due to microphase separation they self-assemble into DNA nanoparticles. These objects were first used as nano-sized reactors for DNA- templated reactions. Reactant DNA was hybridized into the DNA nanoparticles and three different reactions were sequence specifically performed in the corona as well as in the inside of the nanoobjects. Next, the DBC aggregates were subjected to enzymatic reactions. With the help of a template-independent DNA polymerase single-stranded DBC aggregates can be extended under mild conditions leading to a gradual increase in the size of the DNA nanoparticles. Extension of DBCs and DBC aggregates is also possible with template-dependent polymerases. In a PCR process DBCs can act as primers leading to doublestranded DBCs with extended nucleic acid segments and complex multiblock architectures. When primers are labelled with a thermoresponsive polymer segment amplicons can be conveniently separated from the complex PCR reaction mixture by simple heating and centrifugations steps. This technology might have future potential for the accelerated purification of PCR-products. Moreover, we could demonstrate that PCR can be carried out on very small polymer beads, which might be of importance for the improvement of next generation sequencing techniques.