Figure 3.

Fluorophore labeling of two distinct populations of proteins in Rat-1 fibroblasts. Cell were pulse-labeled for 3 h with an amino acid (Pulse A), washed, and then pulse-labeled for 2 h with a second amino acid (Pulse B). Cells were fixed and blocked before dye-labeling for 1 h with 50 µM LR-azide and 1 h with 10 µM DMAC-alkyne. The overlay shows both the DMAC (green) and LR (red) fluorescence. Scale bar represents 20 µm.