Most sample vials are flat-bottomed with straight sides for stability on the bench, although dedicated vial racks can be used. Sample vials are often profiled to minimise dead volumes above the sample surface. Smaller vials may also have conical interiors for improved sample recovery. Sample vials are often supplied in kits in partitioned trays to aid inventory and identification. Sample vials may also be sterile or pre-cleaned for conformity to various certification and compliance requirements.

Glass sample vials made from Type 1 Class A borosilicate glass have low extractables and superior chemical resistance, others made from soda lime glass are for less demanding applications. Plastic sample vials are manufactured from polypropylene, PFA, LDPE or PPCO. Most sample vials are clear, but amber-coloured versions are also available for light-sensitive samples.

Vials are supplied without caps, or else with caps either packaged separately or ready-fitted to minimise contamination. Sample vial caps can be screw-top, friction-fit or snap closure, and made of polythene, polypropylene, black phenolic or aluminium. Caps may be lined with a rubber or a PTFE-faced septum.

What are sample vials used for?

• Sample collection and storage
• Sample preservation, display or exhibition