Tracking Heart Cells with Lasers and the Future of Biophotonics Image Credit: SewCream/Shutterstock.com It is extremely difficult to image single cells inside living animals, but it is necessary to investigate how cells and tissues inside the body function. The use of light-based techniques enables researchers to image, identify and engineer such unique entities, but can only penetrate a certain distance through tissues. New and improved biophonic techniques are needed to help us see further into the body. A team of Scotland researchers believes its new microscopy technique can do just that. Using a micrometer-sized laser, the team was able to track beating-induced changes in the refractive index of heart cells.