All of the trimers are available individually so the researchers can prepare custom trimer mixes. Two pre-made catalog trimer mixes are available: 13-1991-xx, for incorporating all 20 amino acid codons equally into a sequence and 13-1992-xx, for incorporating 19 amino acid codons (-Cys). For a custom trimer mix of a particular subset of codons or a trimer mix that represents a set of trimers that is biased toward a particular codon or codons, please contact [email protected] for a quotation and projected delivery date.