Cellular uptake of TFSMs is affected by fetal bovine serum (FBS). HeLa cells were treated with TFSM 1 in the presence of 1 or 10% FBS for 2 h. Samples were fixed and clicked with AlexaFluor TM (AF)488-DBCO (backbone) or Cy5-azide (headgroup). n = 1. Scale bars: 50 m.
