Choosing a reagent bottle: glass against the plastics and what each one does to the contents, why the closure and its liner decide compatibility more often than the bottle does, and what the label has to carry once anything is decanted into it

Specifying the bottle

1. Choose the material from what goes in it. Borosilicate glass resists solvents and thermal shock and is the default for organic chemistry and for anything autoclaved. High density polyethylene and polypropylene are unbreakable and suit aqueous solutions, with polypropylene tolerating autoclaving. Fluoropolymer bottles handle aggressive chemistry at a much higher cost.
2. Pick the closure and check its liner. The cap is where compatibility usually fails. A polypropylene cap with an inappropriate liner will swell, dissolve or leach into the contents, and for volatile or aggressive material a fluoropolymer-lined closure is what keeps the bottle sealed. Read the liner specification, not the cap material.
3. Use amber or a sleeve where light matters. Photosensitive reagents degrade in a clear bottle on an open shelf faster than most people expect. Amber glass or an opaque overpack is cheap, and moving a stock solution into the dark is the most effective stabilisation available.
4. Match the neck and the thread to the accessories. Thread sizes are standardised, and a bottle that will take a dispenser, a cap with tubing ports or a safety cap for solvent has to match it. Buying a bottle that cannot take the dispenser you own is an avoidable annoyance repeated at scale.
5. Label it the moment anything goes in. Any container holding a hazardous chemical outside immediate use carries the identity, the hazards and the pictograms under the hazard communication rule, plus the date and the person who prepared it for laboratory practice. An unlabelled bottle is the single most common laboratory inspection finding.

Autoclaving, and what survives it

Borosilicate and polypropylene autoclave; polyethylene and polycarbonate generally do not survive repeated cycles. Caps must be loosened, because a sealed bottle in an autoclave is a pressure vessel and behaves like one.

Repeated cycles age plastics and etch glass. Retire bottles on a schedule and inspect glass for star cracks around the base, which is where thermal shock damage shows first.

Secondary containment and storage

Solvent and acid bottles belong in a tray or a cabinet appropriate to the hazard, not on an open shelf above head height. A bottle that falls is a spill; a bottle in a tray that falls is usually just a mess.

Segregate incompatibles in storage rather than alphabetically. Alphabetical shelving of chemicals is how oxidisers end up beside organics.

Buying at volume

Standardising on one or two bottle and closure families across the laboratory means caps interchange, dispensers fit and the stock room holds fewer lines. The saving is in the handling rather than the unit price.

Keep a small stock of the awkward sizes rather than a large stock of everything. The bottle that stops work is almost never the common one.

Common questions

Glass or plastic reagent bottles?

Borosilicate glass for solvents, for anything autoclaved and where leaching must be minimal. Polyethylene or polypropylene for aqueous solutions where breakage is the bigger risk, with polypropylene where autoclaving is needed.

Why did my bottle cap fail?

Almost always the liner rather than the cap. Liners are made from different polymers with very different compatibility, and a liner attacked by the contents leaks, contaminates and can swell enough to jam the closure.

Do I need amber bottles?

For photosensitive reagents, yes, and for anything stored on an open bench for months it is cheap insurance. The alternative is a cupboard, which works just as well if the bottle actually stays in it.

What has to be on the label?

The chemical identity and the hazard information with pictograms, under the hazard communication rule, for any container other than one in immediate use by the person who filled it. Adding the concentration, the date and the preparer's initials is ordinary good practice.

Browse by service class

• Compare Gene synthesis on advertised prices