Rubber Teats

Quick Answer: Rubber Teats are small, thimble-shaped rubber bulbs that fit over the end of a glass dropper or Pasteur pipette. Squeezing and releasing a teat draws liquid in and lets it out drop by drop.

Dropwise Control in Everyday Practicals

Adding indicator to a titration flask, delivering a few drops of reagent in a spot test, or taking a small sample from a culture all rely on a dropper. The teat supplies the suction and the fine control that lets one drop be released at a time. Because teats split, perish or go missing faster than the glass they fit, most labs buy them separately and keep spares near every dropper bottle.

Each teat is sized to the outside diameter of the glass it fits. Too loose and it slips off or leaks air, so liquid dribbles out; too tight and it is hard to fit and more likely to crack the glass as it is pushed on. Glass Pasteur pipettes and dropping tubes are the usual partners, while larger glass pipettes need a pipette bulb instead.

Rubber tolerates water, dilute acids and alkalis, and most indicator solutions, but it is not suited to organic solvents, concentrated acids or strong oxidisers. For those, disposable plastic pipettes avoid the problem.

Applications

• Adding indicator drops to titration flasks
• Spot tests and microscale reactions on a dimple tile
• Taking small samples from a culture or pond-water jar for microscope slides
• Replacing perished teats on the dropper bottles of a reagent set

Care & Handling

• Wet the glass end slightly and roll the teat on rather than forcing it.
• Keep the dropper tip pointing down once liquid is inside, so it cannot run back into the teat.
• Rinse teats in clean water after use and let them dry off the glass.
• Discard teats that are sticky, cracked or slow to spring back.

Specifications

Why Choose LabEquip

Teats are an everyday consumable, so schools and colleges usually order them in quantity with each term’s stock. LabEquip includes them in the General Lab Products range; send the dropper or pipette diameters to be fitted via the contact page.

Frequently Asked Questions

How do I know which teat size fits my dropper?

Measure the outside diameter of the glass where the teat will sit. The teat’s opening should be slightly smaller, so that it stretches on and grips without being forced.

Why does my dropper drip on its own?

Air is leaking in past the teat, usually because it is loose or split, or warm liquid is expanding the air trapped inside. Fit a snugger or new teat and let warm liquids cool before drawing them up.

Can rubber teats be autoclaved?

Some rubber compounds tolerate autoclaving, but repeated cycles make general-purpose rubber sticky or brittle. Check the rating, or use silicone teats where sterilisation is routine.

What liquids should not be used with rubber teats?

Organic solvents such as acetone, chloroform and toluene, concentrated acids and strong oxidisers attack rubber. Use glass syringes or disposable plastic pipettes for these.

Why did the teat fill with liquid?

The dropper was probably tilted upwards or laid flat while full, or too much liquid was drawn up in one go. Keep the tip pointing down and draw up only as much as the glass holds.

How long do rubber teats last?

With rinsing after use and storage away from light and heat, they last many months. Solvents, ozone and sunlight shorten their life, and a sticky or cracked teat should be replaced.

Last Updated: September 2026