The one bead one compound (OBOC) strategy was recognized by Kim S Lam et al. in 19914, although combinatorial on-bead libraries through slit-mixing strategies had been used prior to this. In combinatorial on-bead peptide library formation, allowing each reaction to reach completion results in a final library where each bead present with only one compound. All beads can then be tested and the beads with active compounds can be picked for further analysis. The synthetic strategy used standard Fmoc-based SPPS strategy to produce a library of n-mers. In the CTB lab we use TentaGel beads, that are place in separate reaction vessels and one amino acid per vessel is added. After completion of the reaction, the beads are mixed and separated into new vessels, and again one amino acids is coupled per vessel. This is repeated until the preferred n-mer length is obtained.