Lab vials, predominantly glass vials but also made of other materials, are cylindrical containers used to store liquids such as injectable medicines or vaccines, and solids such as powders or capsules, in laboratories or medical research. Capacities are commonly given in either milliliters or drams, and they can range from less than 0.15mL to more than 150mL or from as little as 0.375 drams up to 32 drams. Vials can be made of glass to contain aggressive chemicals or solvents, or they may be made of plastic such as polypropylene or polyethylene for durability and resistance to some chemicals. Sometimes, glass vials are made of borosilicate glass for heat resistance. Amber-colored glass and plastic provides protection from ultraviolet (UV) rays for light-sensitive samples, materials, or substances. Vial openings may be threaded for use with a screw cap, or plain for use with a snap cap, stopper, or aluminum crimp top. Caps may be lined with rubber, foam faced with PTFE (polytetrafluoroethylene), or plastic, or they may have a hole in the center with a septum to enable access to injectable substances. Some vials have graduations to indicate approximate measurements, marking spots for labeling, or color-coded caps for identification purposes.
Small glass vials and plastic vials are available for an array of specific applications in chemistry, biology, and pharmaceutical industries. Autosampler vials, made of borosilicate glass, are used in chromatography techniques, in which multiple vials are set in a rack and placed in an automated fraction collector and sampler for preparation or analysis. Liquid scintillation vials are made from borosilicate glass or polypropylene and are used to contain radioactive isotope samples during liquid scintillation counting processes. Samples for standard EPA water tests, such as analysis for pollutants or coliform, can be contained in borosilicate glass vials ranging in size from 20mL to 60mL. Polystyrene drosophila vials are clear to provide visibility of fruit flies cultured in a lab for biological or genetic studies.