Increasing the Efficacy of Bioorthogonal Click Reactions for Bioconjugation: A Comparative Study

In a recent paper in Angewandte, the Wu lab compares different reaction conditions for copper-catalyzed and strain-promoted 'click' reaction for different protein bioconjugation purposes. Overall, the efficiency of the Cu-catalyzed reactions is the highest, if an optimal ligand is used: they recommend BTTA. If you are doing 'click' reactions, I highly recommend taking a look at the conditions and experimental procedures in this paper.
The author, Peng Wu, was a Sharpless graduate student and a Bertozzi postdoc, and thus is an expert in [3+2] bioconjugation reactions.