The Salk Institute maintains a central facility for media preparation. The facility, which is located in the new East Building, adjacent to the glassware washing facility, occupies 360 sq.ft. It contains two laminar flow hoods, an autoclave, and a Millipore Milli-Q water purification system. The facility, in addition to providing a reliable supply of standard culture media, prepares specialized media and solutions that are expensive or not readily available commercially for the research programs in a efficient, cost-effective way. Liquid nitrogen and carbon dioxide are dispensed from central sources for use in 11 liquid nitrogen freezers and 73 tissue culture incubators in Cancer Center laboratories. These compressed gases are shared by all investigators.