total amino acid production is used for peptide synthesis. In fact, L-glutamic acid, D, L-methionine, L-aspartic acid and L-phenylalanine are used in large quantities as food and feed additives. About 50 peptide drugs are commercialized. The number of amino acids that make up a specific peptide varies widely. At the low end are the dipeptides. The most important drugs with a dipeptide (L-alanyl-L-proline) moiety are the "-pril" cardiovascular drugs, such as Alapril (lisinopril), Captoril (captopril), Novolac (imidapril) and Renitec (enalapril). Also the artificial sweetener Aspartame (N-L-α-Aspartyl-L-phenylalanine 1-methyl ester) is a dipeptide. At the high end there is the anticoagulant hirudin, MW ≈ 7000, which is composed of 65 amino acids. Apart from pharmaceuticals, peptides are also used for diagnostics and vaccines. The total production volume (excl. Aspartame) of chemically synthesized, pure peptides is about 1500 kilograms and sales approach $500 million on the active pharmaceutical (API) level and $10 billion on the finished drug level, respectively. The bulk of the production of peptide drugs, which comprise also the first generation anti-AIDS drugs, the "...navirs", is outsourced to a few specialized contract manufacturers, such as Bachem, Switzerland; Chengu GT Biochem, China; Chinese Peptide Company, China; Lonza, Switzerland, and Polypeptide, Denmark. Proteins are "very high-molecular-weight" (MW > 100,000) organic compounds, consisting of amino acid sequences linked by peptide bonds. They are essential to the structure and function of all living cells and viruses and are among the most actively studied molecules in biochemistry. They can be made only by advanced biotechnological processes; primarily mammalian cell cultures. Monoclonal antibodies (mAb) prevail among human-made proteins. About a dozen of them are approved as pharmaceuticals. Important modern products are EPO (Binocrit, NeoRecormon, erythropoietin), Enbrel (etanercerpt), Remicade (infliximab); MabThera/Rituxin (rituximab), and Herceptin (trastuzumab). PEGylation is a big step forward regarding administration of peptide and protein drugs. The method offers the two-fold advantage of substituting injection by oral administration and reducing the dosage, and therefore the cost of the treatment. The pioneer company in this field is Prolong Pharmaceuticals which has developed a PEGylated erythropoietin (PEG-EPO). Oligonucleotides are a third category of big molecules. They are oligomers of nucleotides, which in turn are composed of a five-carbon sugar (either ribose or desoxyribose), a nitrogenous base (either a pyrimidine or a purine) and 1–3 phosphate groups. The best known representative of a nucleotide is the coenzyme ATP (=Adenosine triphosphate), MW 507.2. Oligonucleotides are chemically synthesized from protected phosphoramidites