Written and maintained by CASRAI Editorial Board
Last updated
General product information for laboratory and clinic staff; not medical advice and not a procedure guide. Specifications below come from the manufacturer listings named in the Sources section, checked 2026-11-07, and vary by manufacturer.
Overview: what a transfer pipette is and what it is for
A transfer pipette (also spelled transfer pipet, or called a bulb pipette) is a one-piece disposable plastic dropper: a squeezable bulb at one end and a narrow tube at the other. Squeezing and releasing the bulb draws liquid in; squeezing again expels it. Its purpose is to move liquid from one container to another without a separate bulb or a powered device, which is why it replaces the glass Pasteur pipette in many routine tasks. It is a transfer tool, not a precision measuring tool: the printed graduations are rough guides, and drop counts per millilitre are approximate.
The manufacturer listings read for this page describe the material as polyethylene (USA Scientific) or low-density polyethylene, LDPE (Dynarex), and say the plastic will not shatter or break. Dynarex also lists its pipette as DEHP free, transparent and disposable, intended “to help prevent cross-contamination” when each unit is used once.
Sizes: capacity, graduations and bulb draw are three different numbers
The size on the label is the pipette’s total capacity, but the printed graduations often cover only part of it, and the bulb itself may draw less than the full capacity. The USA Scientific 7 mL transfer pipet is a clear example: capacity 7 mL, graduated to 3 mL with marks at 0.5, 1.0, 2.0 and 3.0 mL, bulb draw 3.5 mL, length 16.0 cm, and 21 drops per mL. Reading it as a 7 mL measuring device would be a mistake; only the first 3 mL carries marks.
| Listing | Capacity | Graduations | Material | Sterility as listed |
|---|---|---|---|---|
| USA Scientific, 7 mL graduated | 7 mL | 0.5, 1.0, 2.0, 3.0 mL (to 3 mL) | Polyethylene | Bulk bags non-sterile; bags of 20 and individually wrapped sterile |
| Dynarex LabChoice 40203, small bulb | 3 mL | Molded, fade-resistant (interval not stated) | LDPE, DEHP free | Sterile, ethylene oxide (EO), 1 per pouch |
Dynarex lists the same product family in 1.5 mL (pediatric), 3, 5 and 7 mL sizes, each as sterile and non-sterile versions. No formal standard for transfer pipette dimensions or graduation accuracy appears in these listings, so capacity, bulb size and graduation pattern are set by each manufacturer and should be read from the product’s own specification.
Types table: transfer pipette versus the other pipettes it is confused with
| Name | What it is | Best for | Limits |
|---|---|---|---|
| Transfer pipette | One-piece disposable plastic bulb and tube | Moving liquid between containers; adding or removing drops | Approximate graduations only; not a precision volume tool |
| Pasteur pipette | Glass dropper tube that needs a separate rubber bulb | The same transfer role, where glass is acceptable | Glass can break; needs a separate bulb |
| Serological pipette | Graduated tube for measuring larger volumes, used with a pipette controller | Measuring volumes in millilitres | Needs a controller; see the pipette overview |
| Micropipette | Adjustable piston pipette used with disposable tips | Microlitre volumes | Needs the right tips; see what a micropipette is |
| Repeater pipette | Device that draws a set volume once and dispenses equal portions | Repeated aliquots of the same volume | Uses a dedicated disposable tip; not a one-piece dropper |
What to match when choosing a transfer pipette
Because the listings read for this page state no selection rules, the safest approach is to match the pipette’s stated specification to the job rather than to the setting. These are the attributes the listings actually publish:
- Capacity versus marked range. Compare the capacity with the graduated range (the 7 mL pipette above is marked only to 3 mL).
- Bulb draw. The USA Scientific listing states a 3.5 mL bulb draw for its 7 mL pipette, so a single squeeze draws about half the stated capacity.
- Sterile or non-sterile. Listings sell both, sometimes in the same size.
- Packaging. Bulk bags, bags of 20 and individually wrapped units are offered; individually wrapped units are listed as sterile.
- Material. LDPE or polyethylene; Dynarex lists DEHP free.
What to check on the label
- Total capacity and the graduated range, not capacity alone.
- Sterile or non-sterile, and the sterilisation method where stated (Dynarex states ethylene oxide). Listings can disagree between their description and their specification table, so confirm sterility against the product label.
- Pack format: bulk, bag of 20 or individually wrapped.
- Material and any stated absence of DEHP.
- Whether graduations are printed or molded, and their interval.
Care and replacement
Transfer pipettes are sold as disposable (Dynarex: disposable to help prevent cross-contamination). Treat each one as single-use for one liquid, and discard it as laboratory waste under your facility’s rules once it has contacted a sample or reagent. Never draw liquid by mouth; see why mouth pipetting is prohibited. For tips used with micropipettes, see the pipette tips selection guide.
Frequently asked questions
What is the purpose of a transfer pipette?
A transfer pipette moves small amounts of liquid from one container to another using a built-in squeeze bulb. It is a convenient disposable alternative to a glass Pasteur pipette and its separate bulb, not a device for exact measurement.
How do I read 1000 microliters on a pipette?
1000 microliters (µL) equals 1 millilitre (mL). On a transfer pipette, find the 1 mL graduation if the pipette has one; the 7 mL USA Scientific pipette, for example, is marked at 1.0 mL. On an adjustable micropipette, the volume is set on its dial in the way described in that instrument’s own manual; see what a micropipette is.
What is a pipette repeater?
A repeater pipette is a device that draws liquid once and then dispenses the same set volume repeatedly. Mettler Toledo’s Rainin description says it works with a disposable syringe-style tip whose plastic piston the instrument clamps onto, and is used for tasks such as aliquoting and PCR setup. It is a different tool from a transfer pipette.
How do I use a disposable pipette?
Follow the instructions that come with the pack. In general terms, a one-piece transfer pipette is squeezed at the bulb, the tip is placed in the liquid, the bulb is released to draw liquid, and it is squeezed again over the receiving container. Use a fresh pipette for each different liquid, and do not rely on the graduations for precise volumes.
What is the difference between a transfer pipette and a graduated pipette?
A transfer pipette is a one-piece disposable dropper whose graduations are approximate. A graduated (serological) pipette is a measuring tube used with a controller; see the types table above.
Sources
- USA Scientific, 7 mL Transfer Pipet, Graduated: product listing, read 2026-11-07.
- Dynarex, LabChoice Transfer Pipettes, Small Bulb, Individually Wrapped (40203): product listing, read 2026-11-07.
- Mettler Toledo, Rainin repeater pipettes, read 2026-11-07.
