Pipette, Graduated

Quick Answer: A graduated pipette, also called a measuring pipette, is a straight glass tube marked with a scale along its length, used to measure and deliver variable volumes of liquid. It lets the user dispense any volume within its range by reading the scale.

Specifications

Measuring Any Volume Along a Scale

Where a bulb pipette delivers one fixed volume, a measuring pipette delivers whatever the method needs: 2.5 cubic centimetres of reagent, then 1.2, then 4.0, all from the same pipette. It is a uniform tube with a scale along the stem, and the delivered volume is found from the difference between the starting and finishing readings.

Two patterns are common. In the Mohr type, the scale stops above the tapered tip, so liquid is delivered between two marks and never run out completely. In the serological or blow-out type, the scale runs down to the tip and the last drop is expelled to deliver the full volume. The listing does not state which pattern or capacity is supplied, so confirm both when ordering and learn the delivery method for the pattern you use.

Measuring pipettes are less accurate than bulb pipettes for a single volume, because the scale lies along a wider tube, but they are indispensable for preparing a series of dilutions, adding reagents in varying amounts and experiments in which volumes change from run to run.

Care & Handling

• Read the scale with the pipette vertical and your eye level with the meniscus; a tilted pipette gives a wrong reading.
• Check which way the scale is numbered before use, since some pipettes read from the top down and others the reverse.
• Wash the pipette immediately after using viscous or sticky solutions, which dry inside the narrow bore.
• Store it in a pipette rack or tray with the tip protected from knocks.

Applications

• Making a dilution series, for example of copper(II) sulfate solution for a colour-comparison practical
• Adding varying volumes of acid in rate-of-reaction experiments that change concentration
• Measuring small reagent volumes for qualitative tests and microscale chemistry
• Preparing mixtures for enzyme or buffer experiments in biology and biochemistry

Why Choose LabEquip

School and college laboratories use measuring pipettes wherever volumes vary from one experiment to the next, and biology departments order them alongside chemistry. LabEquip lists them in the chemistry lab equipment range together with the bulb type pipette for fixed volumes; send your capacity requirements via the contact page.

Frequently Asked Questions

What is the difference between a Mohr pipette and a serological pipette?

A Mohr pipette has its scale ending above the tip, so volumes are delivered between two marks. A serological pipette is graduated to the tip, and the final drop is blown out to deliver the full volume.

How do I measure a volume with a graduated pipette?

Fill above the starting mark with a pipette filler, let the liquid down to a chosen starting mark, then deliver until the meniscus reaches the second mark. The difference between the two readings is the volume delivered.

When should I use a bulb pipette instead?

Use a bulb pipette when one fixed volume must be delivered as accurately as possible, such as an aliquot for a titration. Use a measuring pipette when the volume varies or several different volumes are needed.

Why is my pipette delivering the wrong volume?

Common causes are reading the meniscus off-level, letting liquid run past the lower mark on a Mohr pipette, or a greasy bore that leaves droplets behind. Clean glass and a steady, vertical delivery fix most errors.

Can the pipette be used for viscous liquids like glycerol?

It can, but viscous liquids drain slowly and leave a film on the wall, so readings are less accurate. Deliver slowly, allow extra drainage time, and consider weighing the liquid instead where accuracy matters.

How do I clean a graduated pipette?

Rinse it with water straight after use, then soak it in laboratory detergent solution, flush with tap water and finish with distilled water. Let it drain vertically in a rack.

Last Updated: September 2026