Put a straw in a glass of water, press a finger over the top and lift it out. The water stays in the straw until you let go. A serological pipette works the same way, and a pipette controller is the finger on top: a small battery pump that draws liquid up into the pipette and lets it out again, exactly when you want it to.
The surprising part is that nothing actually pulls the liquid up. When you remove air from a straw, the air pressing on the drink outside pushes it in. With a perfect vacuum, sea-level air pressure could push a drink about 10.3 m up a straw.[1] A pipette needs only a tiny slice of that, which is why a pump that fits in your hand is plenty.
So how do you choose a pipette controller (also called a pipette aid or pipette filler)? Check six things: the pipette sizes it accepts, how finely you can control speed, whether it offers both gravity and powered dispensing, battery life, weight in the hand, and how easy the filter is to replace. For daily work an electric controller is the standard choice; a bulb or thumbwheel pump still makes sense for occasional use.
Key takeaways
- Pick a controller that fits every serological pipette size you use, so one tool covers the bench.
- Look for fine, pressure-sensitive speed control; it is what lets you stop exactly on a graduation line.
- You need two ways to empty a pipette: gravity for self-draining pipettes and powered blow-out for pipettes marked with an etched ring.
- Weight, battery life and a replaceable filter matter more than extra features when you pipette all day.
In this guide
What a pipette controller does
Serological pipettes are long, graduated glass or plastic tubes for moving milliliter volumes. You fit the top of the pipette into the controller's soft adaptor, press one trigger to fill and another to dispense. Inside, a small pump and a pair of valves either remove air from the pipette or let it back in.
How a pipette controller draws liquid up
There are three common kinds of pipetting aid:
- Rubber safety bulb: squeeze it to make suction, then press small valves to fill and drain. Cheap and simple, but tiring over many transfers.
- Thumbwheel pipette pump: turning a wheel moves a plunger. Precise for small pipettes, slow for large ones.
- Electric pipette controller: a rechargeable pump with finger triggers. Fast, light on the hand and the usual choice for cell culture and media work.
Why labs stopped pipetting by mouth
For decades, lab workers filled pipettes by mouth, just like a straw. That habit had a cost. A 1951 survey sent to 5,000 laboratories cited 1,342 lab-acquired infections; only 16% were tied to a documented accident, and most of those were related to mouth pipetting and the use of needles and syringes.[2]
Today the rule is short and universal. Standard biosafety practice at every level says mechanical pipetting devices are used and mouth pipetting is prohibited.[2] One university biosafety manual puts it in four words: do not mouth pipette.[6] A pipette controller is simply the most comfortable way to follow that rule hundreds of times a day.
Six things to check before you buy
1. Pipette range and fit
Serological pipettes move volumes from less than 1 mL up to 50 mL, so most labs keep several sizes.[4] A universal silicone adaptor that fits all of them is worth looking for.[3] Check the stated range against your smallest and largest pipettes, and make sure small pipettes seat without leaking air.
2. Speed control
Adjustable speed is what makes accurate aspiration and dispensing possible.[3] Fast is useful for filling a 25 mL pipette; slow is essential for stopping exactly on a graduation line with a 1 mL pipette. The best controllers combine a speed setting with pressure-sensitive triggers, so pressing lightly moves liquid slowly and pressing harder speeds it up.
3. Gravity and powered dispensing
Serological pipettes come in two styles, and they empty differently. A blow-out pipette has a continuous etched ring, or two small close rings, near the top, which means you need to get the last drop of liquid out.[4] Without these markings a pipette is self-draining, and the last drop should not be forced out.[4]
Two ways to empty a serological pipette
That is why a good controller offers two modes. Gravity mode simply vents the pipette so liquid drains under its own weight, ideally with the tip against the inner wall of the receiving vessel and without forcibly expelling the liquid.[6] Powered mode pushes air down to dispense quickly and to blow out the final drop when the pipette is marked for it.
4. Battery life and charging
A controller that dies mid-transfer is more than an annoyance in a biosafety cabinet. Battery life is one of the most important features to compare; look for a unit that holds a charge for many hours of operation.[3] Also check charging time, and whether you can keep working while it charges.
A weak battery costs you more than a recharge. As the charge fades, the pump slows, filling takes longer and it gets harder to stop cleanly on a graduation line. If the controller cuts out with a full pipette in a biosafety cabinet, you have to stop, set the pipette down safely and wait. That is why we gave the Novara PC-100 a lithium-ion battery that runs 12+ hours on one charge, enough for a full day at the bench, and quick-charges over USB-C in 2–3 hours, so a charge overnight has it ready every morning.
5. Weight and ergonomics
Comfort matters because repetitive pipetting can cause strain injuries, so a lightweight, ergonomic design for hours of continuous use is worth paying for.[3] The numbers from one federal ergonomic evaluation of a biological lab show why.
Pipetting-heavy production lab staff: share of the workforce vs share of injuries
Why it matters
In the same evaluation, lab employees performed approximately 6,000 to 11,700 repetitive motions per day involving the pipette.[5]
Hold a controller the way you would at the bench before you buy, if you can. Check that the triggers sit under your index and middle fingers, that it balances without the pipette tipping your wrist, and that it works equally well in either hand if your lab shares equipment.
6. Filter and contamination control
Between the pipette and the pump sits a small filter that stops liquid and aerosols from reaching the mechanism. A replaceable disc filter is a feature worth looking for, because filters do get wet or clogged over time.[3] If liquid is ever drawn up into the filter, stop, replace it and clean the adaptor before you continue. A built-in stand or kickstand that lets you set the controller down with a filled pipette attached is another small detail that saves time.
Bulb, pump or electric? A side-by-side comparison
Here is how the three types of pipetting aid compare on the points that matter most at the bench.
| Feature | Rubber safety bulb | Thumbwheel pipette pump | Electric pipette controller |
|---|---|---|---|
| How it works | Squeeze to make suction; press valves to fill and drain | Turn a wheel to raise or lower a plunger | Battery pump; finger triggers to fill and dispense |
| Pipette sizes | Varies by bulb | Color-coded to a maximum volume, e.g. up to 2, 10 or 25 mL[4] | One unit for 1–100 mL (PC-100) |
| Speed control | Squeeze pressure | Wheel turning rate | Adjustable motor speed |
| Emptying | Valve drain; squeeze to blow out | Reverse the wheel | Gravity or powered (blow-out) |
| Hand effort | High over many transfers | Moderate, thumb-driven | Low; light finger pressure |
| Best fit | Occasional teaching-lab use | Small volumes, infrequent pipetting | Daily cell culture, media prep and repeated transfers |
For most research, clinical and QC labs the electric controller wins on speed and comfort. The Novara™ PC-100 is built around the checklist above: it takes 1–100 mL glass and plastic pipettes, fills 25 mL in under 5 seconds, can dispense as little as 0.1 mL from a 1 mL pipette, offers gravity and electric draining with adjustable, finger-pressure speed control, and weighs 6 oz. Its lithium-ion battery runs 12+ hours and recharges over quick-charging USB-C in 2–3 hours, a replaceable 0.45 µm hydrophobic filter protects the pump, and a built-in retractable kickstand lets you set it down on the bench hands-free.
Tips for accurate, safe serological pipetting
- Check the pipette markings first. Look for an etched ring near the top before you dispense, so you know whether to blow out the last drop or let it stay.
- Pick the smallest pipette that holds your volume. Finer graduations make it easier to stop exactly on the line.
- Read at eye level. Set the bottom of the meniscus on the graduation line with the pipette vertical.
- Start slow, then speed up. Use light trigger pressure near the line and save full speed for bulk filling.
- Dispense against the wall. Touch the tip to the inside of the receiving vessel to reduce splashing and aerosols.
- Never let liquid reach the filter. If it happens, change the filter before the next sample.
- Keep it charged and clean. Charge overnight, wipe the adaptor and housing with a disinfectant compatible with plastics, and replace worn adaptors that no longer grip.
Which pipetting aid fits your lab?
- You pipette milliliter volumes every day, especially in a biosafety cabinet: an electric controller such as the Novara PC-100.
- You transfer media, buffers or cultures in 10–50 mL steps: an electric controller with powered dispensing saves the most time and hand effort.
- You only pipette a few times a week, or need a spare at each student bench: a bulb or thumbwheel pump is a reasonable low-cost option.
- You work in microliters rather than milliliters: a serological pipette is the wrong tool; use a micropipette such as the Novara Digital Electronic Pipette.
Frequently asked questions
What is the best pipette controller?
There is no single best model for every lab. The best pipette controller is the one that fits how you work. If you pipette every day, look for an electric controller that is light in the hand, has fine pressure-sensitive speed control, offers both gravity and blow-out dispensing, runs a full shift on one charge and uses a replaceable filter. If you only pipette occasionally, a bulb or thumbwheel pump may be all you need.
What is the difference between a pipette controller and a pipette?
A serological pipette is the graduated tube that holds and measures the liquid. A pipette controller is the handheld device that fills and empties it. You change pipettes between samples; the controller stays the same.
Do I need gravity mode and blow-out mode?
Yes, if you use more than one style of pipette. Self-draining pipettes should be emptied by gravity without forcing out the last drop, while blow-out pipettes, marked with an etched ring near the top, need that last drop expelled.
How often should I change the filter?
Replace it whenever liquid has been drawn into it, and inspect it as part of routine cleaning. A wet or clogged filter slows filling and can let contamination reach the pump.
Can a pipette controller be used with glass and plastic pipettes?
Most electric controllers accept both. The PC-100 handles 1–100 mL glass and plastic pipettes; check that smaller pipettes seat firmly in the adaptor without leaking air.
Ready to replace a tired bulb or pump? See the Novara PC-100 pipette controller, browse our liquid handling range, or contact our team with your pipette sizes and workflow and we'll help you choose.
References
- Alviar-Agnew M, Agnew H. Extra-long straws. Chemistry LibreTexts, Fundamentals of Chemistry (Palomar College). chem.libretexts.org
- National Research Council. Biosafety in Microbiological and Biomedical Laboratories (Appendix A). Biosafety in the Laboratory: Prudent Practices for the Handling and Disposal of Infectious Materials. National Academies Press, NCBI Bookshelf. 1989. ncbi.nlm.nih.gov
- May M. Picking the best serological pipette controller. Lab Manager. labmanager.com
- Janakiraman R. B7 Pipettes. University of Michigan-Dearborn Science Learning Center. umdearborn.edu
- Hales TR, McGlothlin JD. Ergonomic and epidemiologic evaluation of a biological laboratory. American Industrial Hygiene Conference and Exposition, via CDC Stacks. 1997. stacks.cdc.gov
- Environmental Health and Safety. Chapter 5: Laboratory biosafety practices. Biosafety Manual, University of Nevada, Reno. unr.edu
Figures 1, 2 and 3 were drawn by Novara Scientific from the sources above.
