Facilitate sample lyophilization with freeze-drying flasks, which are used in conjunction with other freeze-drying instruments. The complete freeze-drying flask assembly consists of a top and a bottom, as well as filter paper. Typically cylindrical in shape, the flask bottom can withstand extreme temperatures and high vacuum conditions. The design of the flask top includes an opening that connects to an adapter for attachment of the flask to freeze-drying valves on the instrument. The filter paper, which fits into the top of the flask, prevents product loss during the freeze-drying process.