Bead-based Oligonucleotide Combinatorial Libraries (BOCL) are used for X-Aptamer selections, next generation sequencing (NGS), single cell RNA sequencing, as well as other applications. Attached to each individual bead of a BOCL are many copies of just one oligonucleotide sequence. As many as 1011 beads, each with a unique sequence, are possible in one library depending upon the size of the bead and the scale of the synthesis that a customer desires. AM Biotech has extensive experience with the pool-and-split methodology used to synthesize these libraries, which results in libraries of excellent quality.
The sequences present in a BOCL can be completely random or just partially random. Synthesis can be accomplished using DNA, RNA, or a mixture. In addition, almost any kind of chemical modification can be used. The modifications are most easily inserted if they are available as a phosphoramidite; however, unique post-synthetic modifications can also be included in the oligonucleotide library. AM Biotech has successfully synthesized BOCLs using chemical entities (including peptides) that are not available as phosphoramidites.
Both 3′ to 5′ and 5′ to 3′ synthesis are available. Linkers (standard or custom) that attach the oligonucleotides to the library beads can be cleavable or non-cleavable. AM Biotech has successfully synthesized bead-based combinatorial libraries of over 100 nucleotides in length. AM Biotech can synthesize library batches ranging from 50 mg to >10 g.
A wide variety of supports/beads can be used as the basis of a BOCL (polystyrene, polymethacrylate, controlled pore glass (cleavable), tentagel, etc.). Bead diameter can range from 5 microns to over 100 microns. A wide range of bead pore size is also possible (including non-porous). We have thorough experience developing and sourcing beads and are happy to help customers find the right support for their application.