Common modifications

We offer a wide-range of modifications. Because of the way we make our oligos, we can accommodate specific and unusual modifications (please contact us). This is a list of our most frequently requested modifications.

Fluorescent dyes

FAM, JOE, TAMRA and ROX are the "big four" dyes that have dominated DNA sequencing. The Cy dyes have found widespread use in DNA and RNA labelling.

Fluorescence quenchers

Fluorescence quenchers absorb energy from a fluorophore (fluorescent dye), so that the fluorophore does not emit light when excited by light at a different wavelength. Quenchers operate via two distinct mechanisms: FRET quenching and collisional quenching.

Standard modifications

  • Deoxyinosine
  • Deoxyuridine
  • Amino dU
  • 2-Aminopurine
  • 5-Bromodeoxycytidine
  • 5-Bromodeoxyuridine
  • Aminohexyl (aminolink)
  • Phosphate
  • Thiol
  • Hexaethylene glycol
  • Thiophosphate
  • 5-Iododeoxyuridine
  • 5-Methyldeoxycytidine

Many other modifications are available; please enquire for further details.

Click chemistry

is a relatively new method for labelling oligos and ligating oligos. These modifications prepare oligos for click reactions.

  • Azido dU
  • Octadiynyl dU

Other modifications

Many other modifications are available; please enquire for further details.

Modified sugar phosphate backbones

  • Phosphorothioate DNA
  • 2′-O-methyl RNA
  • RNA

Very many other 3′-, 5′- and internal modifications are possible. Please get in touch for further details, or if you have any questions about the design and synthesis of modified oligonucleotides.