Specimen/Culture Jar/Bottle with Plastic Screw Cap

Quick Answer: This specimen jar with screw cap is a clear glass jar, also called a culture jar or bottle, closed by a plastic screw cap. It holds preserved biological specimens, culture media and field samples in school, college and routine laboratories.

One Container, Three Names

The three names in the title describe the same container in different rooms. On a zoology or botany museum shelf it is a specimen jar holding an organism in preservative; on a microbiology bench it is a culture jar holding broth or agar; on a field trip it is a sample bottle for pond water or soil. Each job needs a clear body to see the contents and a closure that can be opened and resealed many times.

The plastic screw cap is the main difference from older specimen jars with ground-glass stoppers. A threaded cap is quicker to open, does not seize and needs no grease. Its plastic must suit the contents, though: caps on jars of this kind are commonly polypropylene, which tolerates water, dilute acids and alkalis, ethanol and formalin, but softens over time in solvents such as xylene or chloroform.

For insects, seeds or other small material, screw cap vials waste less preservative. Where breakage is the bigger worry, a wide mouth square plastic bottle is a shatter-resistant alternative.

Specifications

Applications

• Keeping preserved animal and plant specimens in ethanol or formalin for biology museums and practical examinations
• Holding broth cultures, agar media or stock solutions that need a larger container than a test tube
• Collecting pond water, hay infusion or soil during field work for later microscopy of protozoa and algae
• Displaying seeds, fruits or life-cycle stages as labelled exhibits

Care & Handling

• Before autoclaving the specimen jar, loosen the screw cap a little so pressure can equalise, and tighten it only after the jar has cooled.
• Check preservative levels each term; ethanol evaporates slowly even under a closed cap.
• Write labels on the glass body rather than the cap, because caps are easily swapped during washing.
• Replace caps that crack or no longer seal; they wear out long before the glass.
• Warm the jar before pouring in hot molten agar, since a sudden temperature change can crack cold glass.

Why Choose LabEquip

Biology departments rehousing a specimen collection and microbiology labs preparing media both order these jars in mixed quantities. LabEquip lists the jar in its Lab Glassware section; share the capacities and numbers you need on the contact us page.

Frequently Asked Questions

What is the difference between a specimen jar and a culture bottle?

Physically very little: the same screw-capped glass container is called a specimen jar when it holds preserved material and a culture bottle when it holds media or growing organisms. The name reflects the use, so one stock item can serve both benches.

Can the jar be autoclaved?

Laboratory glass generally withstands autoclaving, but the plastic cap sets the limit, so check the cap before sterilising. Loosen it slightly during the cycle so steam and air can move, then tighten it once the jar is cool.

Which preservatives are compatible with the plastic cap?

Formalin solutions and 70 per cent ethanol suit polypropylene caps, the common type. Avoid storing xylene, chloroform or other strong organic solvents in the jar, as they soften many plastics and weaken the seal.

How full should a specimen jar be?

Cover the specimen completely with preservative and leave a small air gap under the cap. Any part of a specimen exposed to air dries and discolours, while a jar filled to the brim can leak when warmth makes the liquid expand.

Is a screw cap better than a ground glass stopper?

For routine use, yes: screw caps open easily, do not seize and need no grease. Ground glass stoppers resist organic solvents better, so they remain the choice when a specimen is kept in a solvent that would attack plastic.

How do I clean a jar that held formalin?

Empty the formalin into the designated chemical waste container, rinse the jar and cap several times with water, then wash with detergent and a bottle brush. Wear gloves and work in a ventilated area, because formalin fumes irritate the eyes and airways.

Last Updated: September 2026