This fluorescence micrograph shows the vascular system of a developing chicken embryo, two days after fertilization. Injecting fluorescent dextran revealed the entire vasculature used by the embryo to feed itself from the rich yolk inside the egg.
Caffeine crystals by Annie Cavanagh and David McCarthy. This false-coloured scanning electron micrograph shows caffeine crystals. Caffeine is a bitter, crystalline xanthine alkaloid that acts as a stimulant drug.
A zebrafish embryo is shown 22 hours after fertilization. (Philipp Keller, Bill Lemon, Yinan Wan and Kristin Branson, Janelia Farm Research Campus, Howard Hughes Medical Institute) 11 amazing images from high-powered microscopes - The Washington Post