Self-Avoiding Molecular Recognition Systems (SAMRS).

Reported here is a "Self-Avoiding Molecular Recognition Systems" (SAMRS), a species of DNA that can bind via simple rules to natural DNA but cannot bind to other members of the same SAMRS species. A system having these properties has been achieved with 2-aminopurine-2'-deoxyriboside (A*), 2'-deoxy-2-thiothymidine (T*), 2'-deoxyinosine (G*) and N4-ethyl-2'-deoxycytidine. These were designed to form more stable base pairs with natural complements than with SAMRS complements, based on the number of hydrogen bonds. Thermal melting studies were performed using duplexes containing SAMRS components. All SAMRS species, A*, T*, G* and C*, formed more stable base pairs with natural complements, T, A, C and G than with SAMRS complements, T*, A*, C* and G* respectively. This property of SAMRS would be useful for avoiding to be produced undesired products derived from intra- and intermolecular interaction between primers in multiplexed polymerase chain reactions.