This is a single sample cell used in protein crystal growth experiments on the Space Shuttle. It contained proteins in a solution to stimulate crystal growth. Each cell was installed in a temperature controlled chamber in the protein crystal growth equipment and left alone during the mission. Astronauts activated, monitored by video camera, and deactivated the experiments according to specified temperature and time settings. They also examined the sample cells under a microscope. These experiments enabled researchers to learn which conditions and solutions were best for promoting growth of particular protein crystals. This knowledge is important for medical, drug, and agricultural research. A group of researchers actively involved in experiments for Shuttle flights gave this item and a large set of protein crystal growth equipment to the Museum.