Glen Research offers a unique line of products known as trimer phosphoramidites. These are trinucleotide reagents that allow customers to effectively synthesize oligonucleotides based on amino acid codons rather than individual nucleotides.1 For researchers looking to generate oligonucleotide libraries for mutagenesis, these reagents avoid stop codons and amino acid redundancy. In theory, such libraries can be obtained via a split and pool synthesis workflow without trimer phosphoramidites, but this is very awkward to perform in practice for a large number of codons or longer codon containing regions.