Changes to lipid droplet configuration in mCMV-infected fibroblasts: live cell imaging with simultaneous CARS and two-photon fluorescence microscopy

We have performed multimodal imaging of live fibroblast cells infected by murine cytomegalovirus (mCMV). The infection process was monitored by imaging the two-photon fluorescence signal from a GFP-expressing strain of mCMV, whilst changes to lipid droplet configuration were observed by CARS imaging. This allowed us to identify three visually distinct stages of infection. Quantitative analysis of lipid droplet number and size distributions were obtained from live cells, which showed significant perturbations across the different stages of infection. The CARS and two-photon images were acquired simultaneously and the experimental design allowed incorporation of an environmental control chamber to maintain cell viability. Photodamage to the live cell population was also assessed.