29th August 2018

At Aptamer Group, every custom aptamer project begins with a feasibility study. The target and assay matrix are tested for compatibility and stability with the aptamer library, under a variety of conditions. At this early stage it is important to understand the optimal strategy for the selection, address any potential issues and modify selection variables before beginning the full aptamer development process.

Because aptamers are nucleic acid based, there is sometimes trepidation that they will degrade when exposed to nucleases during the aptamer use. Concern arises when using aptamers in assay matrices containing nucleases (such as serum, plasma, saliva etc) or when aptamers are used as therapeutics or therapeutic delivery vehicles.

Aptamer Group have access to a range of modified nucleotides which are known to result in nuclease resistant aptamers for subsequent use for in vivo screening or therapeutic applications (Figure 1). Incorporation of these modifications is not necessary for shorter assays or target separations. For these applications, the end user simply needs an understanding of how long the Aptamer Group aptamers will be stable, to continue with a project.

Figure 1: Time course stability study of modified RNA in 100% serum over period of 8 hours at 22°C.

As an example of the types of assays completed, a stability study was carried out for a customer with our unmodified aptamer library in the final assay buffer of choice; in this case 100% human plasma, at room temperature. (Figure 2)

Figure 2: Time course stability study of the unmodified aptamer library in buffer vs 100% human plasma at 22°C.

From the data above, you can see the modified library shows no sign of degradation in serum after 8 hours (Figure 1) and the unmodified library is stable in 100% human plasma for at least 4-6 hours at room temperature (Figure 2). Aptamer Group positions every project for success by selecting the appropriate library for the applications and taking the time to explore variables that might affect the selection process; minimizing delays and in conjunction with our automated approach delivering aptamer reagents to our customers as quickly as possible for their research or commercial needs.
If you want to find out more about our processes or discuss how aptamers can be used in your work, please get in touch with us using the form below or call +44 1904 567 790.