X-Aptamers are able to explore new features by utilizing a new selection process. Unlike SELEX, X-Aptamer selection does not rely on multiple repeated rounds of PCR amplification but rather involves a two-step bead-based discovery process. In the primary selection process, combinatorial libraries are created where each bead will carry approximately 10^12 copies of a single sequence. The beads operate as carriers, where the bound sequences will ultimately be detached into solution. In the secondary solution pull-down process, each target will be used to individually pull down the binding sequences from solution. The binding sequences are amplified, sequenced, and analyzed. Sequences that are enriched for each target can then be synthesized and characterized.