We can easily synthesize oligonucleotides having a high number of covalently attached functional groups. By increasing the number of functionalities (reactive groups) on the oligo it is possible to improve the immobilization efficiency of DNA on to chips (Raddatz et al., Nucleic Acids Res., 2002, 30, 4793). Using our MOX/SUC presursor chemistries we are able to design 4, 8, 16, etc functionalities, on the 5′- or 3′-end, or attached through the 2′-position of ribose.

Applications:

Increasing the catalytic potential of nucleic acids
As an example of an artificial ribonuclease we have synthesized a 16-mer deoxyoligonucleotide possessing 16 and 24 imidazole residues, which is a complement to the loop region of tRNAPhe . Our data shows that rapid (30 min), site-specific cleavage can be achieved. Other studies with oligonucleotide conjugates active in cleaving RNA contained fewer imidazole moieties (Beban and Miller, Bioconj. Chem., 2000, 11, 599, Beloglazova et al., FEBS Lett., 2000, 481, 277, Ushijima et al., Biochim Biophys Acta, 1998, 1379, 217), and were more complicated and labor-intensive to make.

Dendrimeric oligonucleotides
Highly branched (dendrimeric) oligonucleotides can be used to amplify radioactive or fluorescent signals (Shchepinov et al., Nucleic Acids Res., 1997, 25, 4447).