Figure 1.

General strategy and workflow of this study. (A) The research question: Which key parameters determine the efficiency of the in vivo performance of tetrazines? (B) We hypothesized that lipophilicity, TPSA, stability, and/or reactivity of the Tz determine its in vivo ligation efficiency. (C) To test this hypothesis, a compound library was created and (D) evaluated with emphasis on the capability for in vivo click reaction. (E) Finally, these results were analyzed to identify and confirm the correlation between key parameters and in vivo ligation performance.