I’m buying a ssDNA library from TriLink and doing SELEX for one target. Assuming I get one specific sequence that will bind with high specificity and affinity. My question is, can I patent that sequence, start conducting a clinical trial and then sell it without permission from TriLink?

Dear Alan,

TriLink does not take any claim on an aptamer sequence determined from one of our Nucleic Acid Libraries for Aptamer Selection. Please let us know if you need any additional information.

Best regards,


I am interested in an aptamer that would be able to detect a Salmonella typhimurium cell at one end and able to specifically hybridize to a ssDNA at the other end. Is it possible for you, and how difficult would that be for such an aptamer to achieve and maintain its 3D conformation in vitro? – Aristea

Dear Aristea,

Thank you for your interest in TriLink BioTechnologies, Inc. Unfortunately, we do not offer aptamer design or selection services. We recommend Base Pair Bio who should be able to help you with your research needs.

We can synthesize the aptamer once the sequence is determined. Please let us know once you have a sequence identified and we will gladly provide a quotation.


I have been reading about aptamers, with the hope of working with them in our lab soon. As I understand, the three dimentional conformation taken up by an aptamer on binding to its target remains the same, through every batch of that aptamer synthesized. I could not however find an article about this. Could you help me with this please? -Swan

Dear Swan,

Thank you for your questions regarding aptamer conformation. Aptamer conformation is not straightforward, as a given sequence can take on multiple conformations. While some aptamers maintain one primary conformation, others do not. The secondary structure can depend on the actual sequence of the apatmer as well as external factors, including the pH and composition of the dilution buffer. In regards to whether aptamers can behave differently due to batch to batch variations, one can imagine a scenario where purity may influence structure and function. However, in general the synthesis should not affect aptamer conformation. Interestingly, we too were not able to easily find any online literature that specifically documents this phenomenon, though The Aptamer Handbook, edited by Sven Klussman presents a lot of useful information on aptamer activity, selection and design.

Please let me know if I can help you further.


How can I design the best flank region with software? – Parisa

Dear Parisa,

Thank you for your question regarding SELEX design. In his 2009 paper titled Design, Synthesis, and Amplification of DNA Pools for In Vitro Selection, Dr. Andrew Ellington suggests using primers of approximately 20 nucleotides due to their melting temperature. To avoid secondary structure formation, he suggests using MIT’s web based program PRIMER3. Please let me know if you have further questions.

Best regards,

Do you know if the aptamers of the SELEX library can distinguish between two peptides with a single aa change, between Gly and Pro. Is there any way compare the likelihood of a certain site to fit such recongnition? Is it different between 20/30/40 nt libraries? Thanks- Eyal

Dear Eyal,
Thank you for your interest in TriLink’s Aptamer Libraries. The complexity of the final library varies with the random region length. Libraries with longer random regions have more unique sequence motifs than libraries with shorter random regions. However, not all possible unique sequences can be represented in each selection. In contrast, libraries with shorter random regions will give you a better representation of all possible sequences but are inherently less complex than a library with a longer randomer region. However, once an aptamer is selected shorter aptamers are easier and less expensive to synthesize

Aptamers have been designed to bind to specific amino acids.Geiger et. al. found an aptamer that distinguished with a 12,000-fold improvement between L-arginine and D-arginine. I don’t know the specific discrimination between Proline and Glycine. It would need to be determined experimentally. Proline and Glycine have different structures but the location within the protein and the protein folding may affect the ability to find an appropriate aptamer.

Good luck with your experiments.

Best regards,
Sabrina Shore, MS