What is air displacement pipetting?

With an air displacement pipette, the piston is moved downward to release a specific volume of air depending on the instrument's volume setting. A partial vacuum is created when the piston rises and liquid is pulled into the pipette. The piston never comes into direct contact with the liquid, thanks to a cushion of air. When dispensing the liquid, the piston descends, and air forces the liquid out of the tip. This process is sometimes repeated in order to ensure no residual liquid is left in the tip.

What is the difference between an air displacement pipette and a positive displacement pipette?

The difference between air displacement pipettes and positive displacement pipetting is how the liquid interacts with the piston. The fluid comes into direct contact with the piston in positive displacement pipettes. On the contrary, air displacement pipettes maintain an air cushion between the piston and the aqueous solution, preventing contamination.

Air Displacement Pipette | Self Contained Pipetting Channels

Hamilton Z-Excursion Universal Sampler (ZEUS) is a fully automated, self-contained air displacement pipette. It is a ready-to-go pipetting channel module for integration into Diagnostics and Life Science instruments. It is based on Hamilton’s revolutionary air displacement pipette technology and uses disposable tips to avoid carry-over. The module is equipped with Qualitative Pipette Monitoring (QPM) which ensures precise and secure pipetting.

Hamilton Air Displacement Pipettes

ZEUS Self-Contained Pipette Channel

The ZEUS pipetting channel is a complete pipetting module with an integrated Z-Axis. This self-contained air displacement pipette performs single sample transfers and multiple dispenses with the highest precision and accuracy.

ZEUS LT Air Displacement Pipette

The ZEUS LT pipetting channel is designed for mounting to an existing Z-Axis. This air displacement pipette utilizes Hamilton’s revolutionary air displacement pipetting technology and CO-RE™ tips.

Pipetting Channel Disposable Tips

Hamilton offers a wide range of pipette tips to address a variety of common automation challenges. Pipetting channel tips are available in a variety of different volumes and packaging options.

Everything You Need to Know About Liquid Handling

Expand your knowledge or brush up on automated liquid handling definitions and best practices in our Everything You Need to Know About Liquid Handling guide.

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Standard and Advanced Air Displacement Pipetting

ZEUS has built-in algorithms for standard and advanced pipetting tasks

Automation engineers looking to integrate pipetting components have traditionally had to invest significant effort into developing algorithms to coordinate a myriad of factors. To address these project risks, Hamilton designed the ZEUS pipetting family with on-board intelligence for industry-leading precision and accuracy. ZEUS air displacement pipettes can meet your advanced and standard pipetting applications.

Qualitative Pipette Monitoring (QPM)

On the STAR Liquid Handling Platform Hamilton pioneered the art of translating pressure curves into intelligent actions. With ZEUS, the benefit of this knowledge is available for integration into any liquid handling application. Some pipetting modules are capable of reporting pressure data. However, ZEUS is the only one capable of interpreting the data and providing actionable information back to the system.

Clogged Tip Detection

If the tip clogs during aspiration the pressure will spike down. As the plunger moves, sample is not being aspirated to help equalize the pressure.

Insufficient Liquid Detection

If there is insufficient liquid in the tube, the pressure curve will start down as normal but then will return to a pressure much higher than the expected level represented by Δp in the graph. The higher pressure is a result of having less liquid in the tip due to an incomplete aspiration.

Aspiration of Foam

If ZEUS pipettes foam instead of liquid, the pressure sensor detects spikes during the aspiration. Based on the severity of the spikes, a threshold can be set for a failed aspiration.

Anti-Droplet Control for Air Displacement Pipetting

Volatile liquids like acetone and methanol can be extremely difficult to pipette using air displacement. These liquids tend to vaporize in the tip which raises the air pressure, resulting in liquid dripping from the tip. ZEUS is equipped with Anti-Droplet Control (ADC). When enabled, the pressure is monitored in the tip. As the pressure rises, the piston is retracted to equalize the pressure and prevent dripping. The illustrations show the pressure curve when ADC is on and off.

ADC OFF

Pressure reaches a maximum; a droplet is lost and pressure drops.

ADC ON

Piston retracts when pressure threshold is reached so no droplet forms.

Resources

Featured Download

ZEUS Family Brochure

Get to market faster by leveraging ZEUS on-board pipetting intelligence and Hamilton depth of pipetting knowledge.

Catalog - Liquid Handling Components

A quick guide to all Hamilton liquid handling components. Learn about air displacement vs liquid filled systems and the correct application of each.

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