Cancer research is an important field of research which investigates the causes of cancer and develops methods for treatment. The development and spread of cancer is a dynamic process which starts within the genes of a cell or a group of cells.
Integrated correlative light and electron microscopy (CLEM) - which combines a fluorescence with a scanning electron microscope into one system - is an important tool for making the discoveries needed to work towards innovative prevention and treatment strategies.
Over the years, correlative imaging has constantly been gaining popularity in the field of cancer research. An integrated CLEM system offers the following benefits:
Seeing rare and transient events of the disease process, such as invasion, metastasis, and how cells respond to treatment
Understanding the behavior of cells within the environment of cancer cells by correlating function to structure
Identifying a region of interest
Figure 1: Localization of the lipid diacylglycerol within cellular membranes of HeLa cell expressing GFP-C1, imaged with the SECOM correlative light and electron microscope at the Francis Crick Institute for research on cancer.
In a study exploring possibilities for targeted breast cancer therapy, the ability to highlight regions of interest at a high resolution was essential. In this research, breast cancer cells were exposed to fluorescently-labelled RGD-targeted Zinc Oxide (ZnO) nanoparticles, already recognized as an important tool for cancer treatment.
Correlative light and electron microscopy was able to demonstrate that the ZnO nanoparticles dissolved into Zn2+ upon uptake by the cancer cells when blue was expressed, followed by the color red at apoptosis, or cell death. The authors stress the importance of an integrated microscopy solution for developing effective treatments at the cellular level. 
Figure 3: Hela Kyoto cells stably expressing GalNAC-T2-GFP and Histone 2B-mcherry, imaged using the SECOM correlative light and electron microscope. Sample courtesy: P. Ronchi & Y. Schwab, EMBL.