Figure 4. Label-free imaging of TM cells using CARS and collagen extracellular matrix using TPAF. The image is taken using a 60× 1.2 NA water objective with 3× digital zoom. (RED: CARS. Green: TPAF). A: Both CARS and TPAF channels are displayed in the image, clearly showing the TM cells in the CARS channel with arrows indicating the TM cells. B: Only the TPAF channel is displayed and TM cells are not observed, indicating that signal of the TM cells are unique to the CARS signal.