Figure 1: Side-by-side comparison of actual mass spectra from a traditional, dispersed PEG (left spectrum) and a dPEG® of equivalent mass from Quanta BioDesign (right spectrum). The mass spectrum on the left is of PEG1000. It has Mw = 1027 Daltons; Mn = 888 Daltons; and Đ = 1.16. The masses in this dispersed PEG range from 600 – 1500 Daltons. The mass spectrum on the right is of Quanta BioDesign product number 10317, amino-dPEG®24-acid, the structure of which is shown across the top of the two mass spectra. PN10317 is a single molecular weight compound with a single, discrete chain length. The molecular weight of PN10317 is 1146.355 Daltons. Because it has no dispersity, Đ = 1.