4th May 2017

At Aptamer Group, we employ state-of-the-art methods to select and identify aptamers to small molecule targets. These aptamers can then be modified to achieve goals that are often not possible with other binding molecule technologies.

Challenges with Small Molecule Targets

The accepted approach for the development of antibodies is to prepare small molecule-protein conjugates. However, these haptens do not represent species which exist in native biological systems. Additionally, the immune response elicited often results in antibodies that recognise the conjugate, rather than the small molecule of interest.

For aptamer selection, the chemistry required for target immobilisation can hinder by preventing aptamers wrapping around the small molecule target. Also, small molecules may lack the necessary functional groups to be immobilised.

A small molecule binding aptamer

A small molecule binding aptamer.

The Solution: Aptamer Displacement Selection Method

To ensure that the aptamers selected have the most desirable characteristics, the small molecule target is presented in solution. To achieve this, the aptamer library is bound to immobilised ‘capture’ molecules with a predefined affinity. When the small molecule target is introduced to the system, aptamers with a greater affinity to the target will dissociate from the immobilisation molecule and bind to the target. The aptamers are subjected to several rounds of exposure to the target molecule, with stringency measures being adjusted to optimise aptamer–target affinity and enable selection of the best possible aptamers for the intended end use.

For details about this process and case study data, please click the following link: Aptamer Group – Small Molecule Selection

Applications for Small Molecule Detection

During small molecule binding, aptamers undergo structure-switching. This can be exploited in a variety of detection methods. We will be pleased to discuss potential applications.

Contact Aptamer Group to explore how aptamers can support your research and development objectives.