Application of L-DNA as a molecular tag.

Enantiomeric DNA termed as L-DNA has unique properties. One is the ability of hybridizing to the complementary DNA as natural D-DNA. Another property is that the L-DNA could be recognized much more weakly by enzymes than D-DNA. We have focused our attention on these properties and applied L-DNA as a molecular tag. Here, we report that L-D chimera DNA is useful for PCR primers and subsequent separation and hybridization. Precise investigation revealed that in the process of PCR, L-DNA region could not be the PCR template and the polymerase extension reaction stopped at the boundary between L- and D-DNA region. As a result, L-DNA region formed like a "sticky end" and played a role of molecular tag. According to the L-DNA tag sequence, the produced L-DNA-tagged PCR products were easily separated or hybridized on the solid surface where the complementary L-DNA was pre-immobilized.