Cell screens can be included in the aptamer discovery process, providing built-in validation for your binder.

In most affinity ligand discovery processes, whether for antibodies or antibody alternatives, the target is typically a single protein or a portion of it. For example, antibodies are usually generated by immunising an animal host with a peptide fragment. This can give perfect reagents for protein analysis or diagnostics, where you only examine the protein in a solution, like Western blots or lateral flow. But scientists who work with cell assays, tissue samples, or in therapeutic development need more.

The fact that many reagents don’t perform in assays like flow cytometry, immunohistochemistry, or cell internalisation reflects the difference between a natively expressed protein on a cell surface and proteins or peptide fragments in solution. Structure can change – the portion of the protein you need for the reagent to bind might be inaccessible and stuck inside a membrane or the folded protein shape, or it may be that the assay conditions have changed the protein, often seen in processes like IHC fixation.

Assured aptamer performance with cell screening in discovery

In our aptamer discovery process we include selections against cells to validate each aptamer during the discovery process. This includes positively expressing cells and null expressing cells, making sure of aptamer selectivity as well as its ability to bind the cell surface target. Doing this means we de-risk the development process and your research time all in one step.

Unlimited by application

With our aptamer development for specific targets, we typically start the discovery process to a protein, with counter-selection to homologous proteins and the assay matrix to drive specificity. This discovery process is then completed using both positive and negative expressing cells to make sure the selected aptamer binders specifically recognise the cell-expressed form of the antigen.

We can extend this further with application specific steps in the cell-screening phase, like using fixed cells or tissues for the discovery of aptamer for IHC or for aptamer internalisation to support therapeutic delivery vehicles. Tailoring aptamer discovery in this way tunes the binder to your specific application needs, overcoming limitations like fixation in IHC processes that can hamper your experiments.

To add to this and further de-risk your aptamer discovery efforts, we also have a complete validatory toolkit to support aptamer characterisation and assay development that can provide the final polishes and deliver you not only a binder with assured performance but protocol support to get to work right away.

Unlimited by target

As aptamers are discovered and developed in vitro, it allows scientists to pursue new targets, such as lowly immunogenic proteins, toxic proteins and small molecules. Aptamer development for all of these target types can include cell screening steps for enhanced validation.

Equally, if you find that your protein target is scarce and getting hold of enough of it to begin an aptamer development campaign is difficult, we can switch the process around and start using cell screens against positive or over-expressing cells vs null cells to develop binders.

Unlimited performance

We understand the challenge of finding the right affinity ligand that is highly specific and sensitive to your intended target. Only Optimer, (Aptamer Group’s own optimised aptamers) offers three distinct and target-tuned discovery processes that can be used alone or in parallel for built-in validation and increased confidence in the performance of your final binder. Not only does including cell-based screens in the discovery process de-risk your binder for cell and tissue applications but it is carried out in a custom way to suit your target and application for that extra piece of mind.

Don’t be limited by standard reagent development. To explore how Optimer can make your science unlimited, get in touch today.

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