This image is of an emulsion of protein solution within oil captured within a glass tube. Like salts, proteins also form crystals, and within each of these droplets, a protein crystal has formed. I took this image as a part of a time lapse to track how long it took for protein crystals to form within drops in order to measure protein nucleation kinetics. The protein used here is lysozyme, which is a model protein used for crystallization research.  The most exciting thing about this image is the repeatable way crystals have grown perfectly one within each identical droplet.