Glassware selection: matching the container to the workflow

Container choice is rarely the interesting part of a protocol, which is why it quietly causes so much rework.

Clear or amber

Amber glass reduces light transmission. If a workflow is light-sensitive, or the item sits on an open shelf under laboratory lighting, amber removes a variable. If you need to see the contents at a glance, clear glass is more practical. Choose deliberately rather than by whatever is in the cupboard.

Crimp or screw

Crimp seals are tamper-evident and consistent, but need a crimping tool and are single-use. Screw closures are re-closable and quicker at the bench, at the cost of depending on operator torque. Neither is better in the abstract.

Dimensional consistency

Vials with the same nominal volume from different suppliers are frequently a millimetre or two apart in height or diameter. That difference is enough to stop an autosampler tray seating properly or to make a rack unusable. When a workflow depends on automation, source matched glassware and keep it matched.

Plan for storage from the start

Choose the rack or box at the same time as the vial. Retrofitting storage around glassware you already bought is how benches end up with four incompatible rack systems.

Equipment selection guidance for laboratory workflows. Nothing here relates to human or veterinary use.