Dendrimer‐Based Signal Amplification of Click‐Labelled DNA in Situ

The in vivo incorporation of alkyne‐modified bases into the genome of cells is today the basis for the efficient detection of cell proliferation. Cells are grown in the presence of ethinyl‐dU (EdU), fixed and permeabilised. The incorporated alkynes are then efficiently detected by using azide‐containing fluorophores and the Cu^I‐catalysed alkyne–azide click reaction. For a world in which constant improvement in the sensitivity of a given method is driving diagnostic advancement, we developed azide‐ and alkyne‐modified dendrimers that allow the establishment of sandwich‐type detection assays that show significantly improved signal intensities and signal‐to‐noise ratios far beyond that which is currently possible.