Generation of Diversely Functionalized DNA Libraries Using Ligase-Catalyzed Oligonucleotide Polymerization (LOOPER).

Ligase-catalyzed oligonucleotide polymerization (LOOPER) enables the synthesis of highly modified nucleic acid libraries, which can be used as pools to evolve functional nucleic acids, such as aptamers. Here, we describe the process to generate a LOOPER-derived ssDNA library comprising 16 different chemical modifications installed in a sequence-defined manner. The preparation of the building blocks, their templated polymerization, and strand separation to generate the modified ssDNA library are outlined.