We understand you are looking to perform an aptamer selection for a metabolite of interest. Once selected, you will put this into one of the intergenic regions. In the absence of metabolite, this region will be linear, while in the presence of metabolite, this region will fold into a complex structure. The presence of this structure will then block translation. Therefore, we believe you are asking if you can design your aptamer library to have a 5’- and 3’- end that is fixed to match the intergenic sequences, with a random number of nucleotides (N20, N30) in between. And the answer to this is yes! We would be happy to make a custom library for you. This construct can be priced and ordered through OligoBuilder.