Vessels used for containing liquids and performing mixing, heating, cooling, incubation, filtration, storage, distillation, volume measurement, and other common liquid handling processes.

The variety of laboratory flasks includes boiling flasks, cell culture flasks, distilling flasks, Erlenmeyer flasks, filtering flasks, freeze drying flasks, Kjeldahl flasks, recovery flasks, and volumetric flasks. Manufactured from a variety of materials, flasks are typically made of glass or plastic resins such as polystyrene, polypropylene, polycarbonate, polymethylpentene, or PTFE. Depending on their application, flasks can be sealed with various closures, including air-tight screw caps, vent caps, and stoppers made of ground glass, glass, plastic, or rubber.

Laboratory flasks are found in most chemical, biological, clinical, and industrial laboratories and in a variety of other workplace settings. They are available in a range of capacities ranging from 10 mL up to 10 L. Depending on the type, they may be supplied with a jointed ground glass top, a glass or plastic stopper, or a screw top.

What Styles of Laboratory Flask Are Available?
• Erlenmeyer flasks are conical and are used for a wide range of purposes; they are graduated and available in narrow-neck or wide-neck versions
• Büchner flasks are also conical, but with a side-arm to accept tubing for vacuum applications and extra-thick walls for increased strength when operating under reduced pressure
• Round-bottomed flasks, including retort and Kjeldahl flasks, are used in chemistry laboratories for reaction, digestion, or heating, and may have up to three necks for connecting to inlet/outlet tubing and other vessels
• Volumetric flasks are used to prepare standard solutions. They are supplied with precise, one-mark graduations and a stopper, and are designated as Class A or Class B depending on their accuracy. Standard measuring flasks are also offered for less critical measurements
• Cell culture flasks are often supplied with specialized cell-adherent treated surfaces and vented filters. They are normally sterile and may have baffled bases for improved aeration during agitation