Two-photon mCherry (red) fluorescence from a 5 days old zebrafish larva. The left images are composed of 20 frames of 300x300 µm² each. The scale bars correspond to 100 µm. The upper left image shows the red fluorescence from mCherry-labelled cells, with the contrast set such that only the brightest cells (central nervous system cells, blue arrows) are slightly saturated. The lower left image has the brightness setting increased, such that finer structures with weaker fluorescence, for example from the cell walls of the notochord (red arrows), just below the bright spinal cord, can be seen. The upper and lower right images show a zoom of the dashed boxes indicated in the respective left images.

Image of a 5 days old zebrafish larva’s tail (left) and 2 days old larva’s muscle tissue (right). The FOV of both images is 300x300 µm², the images are composed of 100 and 77 frames respectively. The green line structures are resulting from second harmonic radiation generated from collagen fibrils. The red structures are due to two-photon fluorescence from mCherry labelled cells. The (large) bright green/yellow structures visible are pigmented cells with stronger scattering.