Enzyme Linked Oligonucleotide Assays (ELONA)

The development of an ELISA can be time-consuming and heavily dependent on the availability of high quality antibodies with validation in an ELISA platform. This is complicated further by the requirement for a reporter molecule, limiting the choice of antibodies and introducing more chance of error in reporting due to non-specific binding. Using aptamers can be beneficial through Enzyme-Linked Oligonucleotise Assays (ELONA)

Aptamers can easily be incorporated into existing ELISA platforms. The resulting assays are known as ELONA and benefit from:

  • Increased sensitivity– using the principle of counter-selection, aptamers can be designed to not recognise closely-related compounds
  • Wider range of outputs– aptamers can be conjugated to multiple reporter molecules including fluorophores, biotin and quencher molecules
  • Easier to develop– aptamer selection identifies multiple aptamers capable of binding to different epitopes on the target’s surface, allowing a pair to be easily determined.
  • Works with existing technology– can be used by all existing plate reader models and ELONA can be designed using existing high-quality monoclonal antibodies.


Example of in-house developed indirect ELONA. Three different human proteins were biotinylated and adhered to a 96-well plate. Aptamers raised against these proteins were conjugated to biotin and incubated with the target in varying concentrations for X hour. A reporter molecule (streptavidin-HRP conjugate) was added with a commercially available reagent and the respective colour change measured using a plate reader.