Custom aptamer selection & characterization

Custom aptamer selection & characterization

Custom aptamer development

Novaptech selects aptamers against any kind of target : small natural or synthetic molecules, peptides, proteins, non pathogenic viruses and bacteria, eukaryotic cells.
We use proprietary libraries with random window of variable size according to the customer’s need.
We select DNA, RNA or chemically-modified RNA aptamers.
We characterize the selected aptamers with respect to their binding properties and specificity of interaction with their target using Surface Plasmon Resonance or fluorescence emission.
We optimize the selected aptamer for easy and cost-effective synthesis and improved properties.
We provide samples of the selected and characterized aptamers through our partnership with Eurogentec. Multiple kind of chemically-modified aptamers can be provided in small or large amounts, under GMP conditions if required.

Eligible targets


Small natural or synthetic molecules






Virus & bacteria


Eukaryotic cells

Our process

Our selection process is divided into successive and independent phases.
A scientific report is provided after each phase that ends with a Go/noGo.

Feasibility study

0 - Feasibility study

Detailed discussion with a Novaptech senior scientist for defining the procedure and the conditions with respect to the customer’s goal.

Initial screening

1 - Initial screening

Iterative steps of selection and amplification over a few rounds under increasing stringency. Selection may be run in parallel under different conditions. Counter (negative) selection can be introduced. The average properties of the pools are evaluated.

Selection of polyclonal aptamers

2 - Selection of polyclonal aptamers

Additional rounds of selection are performed, from the phase 1 pool displaying interesting properties. Pools are analysed by Next Generation Sequencing. Candidates of interest are identified by bioinformatics (sequence homology, round to round evolution, secondary structure prediction)

Characterization of monoclonal aptamers

3 - Characterization of monoclonal aptamers

A few representative candidates identified in phase 2 are synthesized and evaluated with respect to affinity and specificity of interaction with the target. The sequence of the best aptamer(s) is provided.

Optimization of the selected aptamer

4 - Optimization of the selected aptamer

The selected aptamers can be further optimized depending on the type of assay they will be used in. The crude selected aptamer can be trimmed for eliminating portions not necessary for binding. The resulting truncated aptamer can then be chemically modified or conjugated to various pending groups for making it resistant to nucleases or for detection by fluorescence, for instance. Other modifications can be introduced and tested.

Aptamer synthesis

5 - Aptamer synthesis

Novaptech provides a tiny amount of the selected aptamer to the customer for the first trials. Larger amounts of aptamer with numerous chemical modification can be obtained from our partner, Eurogentec

Novaptech added-value

Scientist-to-scientist interactions

Scientist-to-scientist interactions

With Novaptech you benefit from more than 26 years experience on aptamers. From the very early stage of your project you have a personal contact with one of our senior scientists for evaluating the feasibility, designing the library and the selection procedure, defining the chemical modifications and the assay. Feedback is provided at every step of your project.

Cutting-edge aptamer technologies

Our R&D researchers work on innovative processes for aptamer selection and  assay design that are immediately offered to our customers. At Novaptech activity is focused on a particular class of structure-switching aptamers taking advantage of the unique « switch-kiss » technology.

French Research Tax Credit certified

French Research Tax Credit certified

Novaptehc is a CRO certified for research tax credit for years 2020, 2021, 2022, 2023 and 2024.

Industrial capacities through Eurogentec

Industrial capacities through Eurogentec

Eurogentec provides products and services to scientists involved in life science research, molecular diagnostics and therapeutic developments. Expert in small and large-scale synthesis, Eurogentec produces a wide range of custom oligonucleotides from classical primers up to highly complex sequences. Novaptech and Eurogentec signed a partnership for the production of aptamers selected by Novaptech.

Tell us about your target

Any question about selection service or assay development ? Please fill in the form below with relevant details for helping us providing an informative answer. Telephone call can be arranged. NDA can be signed, would you wish so. We will answer you as quickly as possible (generally less than 2 working days).

Contact us
Jean-Jacques Toulmé, PhD, CSO

Your scientific contact :

Jean-Jacques Toulmé, PhD, CSO

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