The term "dPEG^®" is Quanta BioDesigns trademarked acronym for "discrete poly（ethylene glycol）" or "discrete PEG". Each of our products represents a single compound with a unique, specific, single molecular weight （MW） PEG synthesized de novo from pure, small units （e.g., triethylene glycol or tetraethylene glycol）. In our numbering system, we name compounds as dPEG^®nn, where nn stands for the number of oxygen atoms in the spacer unit. We do this in order to simplify the naming of the compounds. Our catalog has the exact structure of the single compound. Thus, for example, product number 10244, amino-dPEG^®₄-acid, has an amino group on one end, four （4） ethylene oxide units, and a carboxylic acid group on the other end, as shown beside:

Some people prefer the term "monodisperse" to describe these PEG compounds. While not an inappropriate term, "monodisperse" implies either that

1. the compounds are single compounds purified from a polymeric mixture, or
2. there is only one compound formed from a polymeric process, which is purely a theoretical concept. We prefer the term "discrete", since these compounds are synthesized as single MW compounds from pure starting materials via standard organic methodology. A discrete PEG is a single compound having no other PEG homologues in it.