The triazole forming cycloadditon reaction of azides and alkynes has been used in many areas of drug discovery. Recently, Sharpless et al. have done these reactions in the presence of enzymes to produce target specific, high affinity inhibitors. However, very low levels of in situ-formed triazoles are produced. In the course of our drug discovery research, we found that it is possible to be misled by artifacts due to the low conversion levels seen for this process.