Dropper

Quick Answer: A laboratory dropper is a narrow tube with a squeezable rubber teat. It draws up a small amount of liquid and releases it one drop at a time, for adding indicators, transferring small samples and making dropwise additions in chemistry and biology practicals.

How a Laboratory Dropper Works

The dropper, sometimes called a teat pipette, works by displacement. You squeeze the rubber teat, dip the tip into the liquid and release the teat gently so liquid is drawn into the tube. Pressing the teat again pushes the liquid out through the narrow tip, and light, controlled pressure lets it fall as separate drops.

This makes it the right tool whenever drops matter more than millilitres. Students use it to add phenolphthalein or methyl orange to a titration flask, to add a reagent drop by drop until a precipitate or colour change appears, and to move a small amount of solution onto a spotting tile or into a test tube. It is not a measuring instrument, so work that needs a known volume belongs with a pipette or burette.

In a teaching lab the dropper usually sits alongside reagent bottles. Schools that want to cut contamination of stock solutions often pair loose droppers with dropping bottles, which keep a dedicated dropper with each reagent.

Specifications

Applications

• Adding indicator solution to a conical flask before an acid-base titration
• Dropwise addition of reagents in qualitative inorganic analysis, such as testing for precipitates
• Placing a drop of sample on a slide or spotting tile for observation
• Transferring small amounts of liquid between test tubes during biology and chemistry practicals

Care & Handling

• Keep the dropper tip-down while it holds liquid so the liquid cannot run into the teat.
• Use a separate dropper for each reagent, and never return a used dropper to a stock bottle.
• Take the teat off for cleaning, rinse both parts with water and then distilled water, and dry them before reassembling.
• Handle the tapered tip with care and store droppers in a tray or rack so the tip is not chipped.

Why Choose LabEquip

LabEquip supplies droppers to schools and colleges equipping chemistry and biology practical benches, together with the rest of their lab glassware. If you need finer control, compare the glass dropper pipette, and contact us with your quantity and preferred size for a quotation.

Frequently Asked Questions

What is a laboratory dropper used for?

A dropper transfers small amounts of liquid one drop at a time. Typical uses are adding indicator to a titration flask, moving a few drops of sample between test tubes, and adding reagents dropwise during qualitative tests where the reaction has to be watched as each drop goes in.

Can a dropper be used to measure an exact volume?

No. Drop size depends on the bore of the tip, the angle the dropper is held at and the surface tension of the liquid, so drops are not a reliable unit of volume. Where an exact volume matters, use a graduated or volumetric pipette or a burette instead.

How is a dropper different from a dropping bottle?

A dropper is a separate tool that is filled from a reagent bottle and then emptied where it is needed. A dropping bottle keeps the reagent in the bottle and dispenses it through its own dropper or dropping stopper, which reduces the risk of contaminating the stock solution in teaching labs.

Which liquids can damage the rubber teat?

Natural rubber teats are generally attacked by many organic solvents, such as hydrocarbons and chlorinated solvents, and can swell, soften or crack. Keep liquid out of the teat, and use a different transfer method for solvents that rubber does not tolerate.

How do you avoid contaminating a reagent with a dropper?

Use one dropper per reagent, never put a used dropper back into a stock bottle, and hold the dropper tip-down so liquid does not run back into the teat. Rinse it with distilled water between uses if it has to be reused for the same solution.

How should a dropper be cleaned after use?

Remove the teat, rinse the tube with water and then distilled water, and let both parts dry before refitting them. A pipette brush or a gentle detergent soak can help if residue remains in the tube. Check the teat for cracks or stickiness and replace it if it no longer draws liquid cleanly.

Last Updated: September 2026