What is a Pipette?

A pipette is a precision instrument designed to accurately measure and transfer small volumes of liquid. Whether you’re pipetting enzymes, reagents, or cell cultures, understanding pipettes is fundamental to achieving reliable and reproducible results in your lab.

Types of Pipettes

Pipettes are essential laboratory tools. The main types we encounter on a day-to-day are volumetric pipettes, graduated pipettes, micropipettes, pasteur pipettes, serological pipettes, electronic pipettes and positive displacement pipettes. Mason Technology partners with leading Pipette suppliers Eppendorf and Labnet, to bring our customers a varied portfolio of Manual and Electronic Pipettes to suit a variety of Pipette requirements.

Volumetric Pipettes

Design:

Volumetric Pipettes have a single graduation mark near the top. They deliver a fixed volume of liquid.

Use Cases:

• • Precise measurement of a specific volume (e.g., 10 mL or 25 mL).
  • Commonly used for preparing standard solutions.

Application Examples:

• • Creation of serial dilutions and stock solutions.
  • Titrations and volumetric analysis.

How do Volumetric Pipettes work?

Working Principle:

They offer highly accurate volume measurement. They have a large bulb with a long, narrow portion calibrated for a specific volume (e.g., 10, 25, or 50 mL).

Process:

To use, draw up the liquid to the calibration mark, then release it into the receiving vessel. These are commonly used in analytical chemistry for preparing laboratory solutions and titrations.

Graduated Pipettes (Mohr)

Design:

Graduated Pipettes have multiple graduation marks along their length. You can adjust the volume by choosing the appropriate mark.

Use Cases:

• • Delivering variable volumes within a specified range.
  • Useful for titrations and serial dilutions.

Application Examples:

• • Adding culture media to cells.

How do Graduated Pipettes (Mohr) work?

Working Principle:

They have straight-walled tubes with uniform graduation marks along their length. They are less accurate than volumetric but still useful for various applications.

Process:

They are commonly used in titrations and clinical analyses. They allow bidirectional measurement and controlled liquid flow.

Micropipettes (Air Displacement Pipettes)

Design:

Micropipettes are precision instruments for microliter (µL) volumes.

Piston-Driven Mechanism: They contains a piston that moves up and down within the shaft

No Direct Contact:  The liquid remains separated from the piston by an air cushion, preventing direct contact.

Subtypes:

Single-Channel:

• • Dispense a single volume at a time.
  • Commonly used in molecular biology and biochemistry.

Multi-Channel:

• • Simultaneously dispense multiple samples (e.g., 8 or 12 channels).
  • Efficient for high-throughput work.

Use Cases:

• • Routine Lab Work: Dispensing small amounts of aqueous or non-viscous liquids.
  • Contamination-Sensitive Applications: Ensuring contamination-free liquid handling.
  • Cost-Effective Solutions: When specialized capillary piston tips aren’t necessary

Application Examples:

• • Serial Dilutions
  • ELISA plate preparation

How do Micropipettes work?

Working Principle:

They are adjustable volume, and used for precise measurements in microliters (µL). They rely on air displacement or positive displacement methods.

Process:

Set the desired volume, aspirate the liquid, and dispense it accurately. These are essential in molecular biology, PCR, and other sensitive assays.

Pasteur Pipettes (Transfer)

Design:

Pasteur Pipettes are simple glass or plastic tubes with a tapered end.

Use Cases:

• • Transferring small volumes (usually drops) without precise measurement.
  • Ideal for transferring liquids between containers.

Application Examples:

• • Blood sampling: They are used to precisely collect blood samples for diagnostic tests, monitoring a patient’s condition or conducting blood transfusions.

How do Pasteur Pipettes (Transfer) work?

Working Principle:

They are disposable plastic devices that transfer small quantities of liquid without cross-contamination.

Process:

These are commonly used for rough measurements in urinalysis, hematology, immunology, and blood banking.

Serological Pipettes

Design:

Graduated Pipette with a wide bore and a bulb at the top.

Use Cases:

• • Dispensing larger volumes (e.g., 5 mL, 10 mL or 25 mL).
  • Commonly used in cell culture and media preparation.

Application Examples:

• • Adding culture media to cells.

How do Serological Pipettes work?

Working Principle:

They transfer liquids measured in milliliters (mL) using an air displacement method. They are calibrated to the tip and commonly used in cell culture, urinalysis, and blood banking.

Process:

Dispense and aspirate liquids accurately. They can mix reagents, cell suspensions, and chemical solutions.

Electronic Pipettes

Design:

• • Fully Electronic: This type has motorized components for aspiration and dispensing. They feature an intuitive interface with a digital display for volume selection.
  • Battery-Powered: They are portable and don’t require a separate power source during use.
  • Memory Function: Some models allow you to save pipetting protocols, making repetitive tasks more efficient.

Use Cases:

• • Repetitive Pipetting: They excel in high-throughput workflows, such as ELISA assays, PCR setup, and plate filling.
  • Volatile Solutions: Unlike air-displacement, these can handle volatile liquids without leakage.
  • Viscous Solutions: They work well with both aqueous and non-aqueous viscous solutions (e.g., glycerol, buffers) due to their consistent performance.
  • Ease of Calibration: Electronic pipettes simplify calibration and ensure accurate results.

Application Examples:

• • Serial Dilutions
  • ELISA plate preparation

How do Electronic Pipettes work?

Working Principle:

They use a battery-powered motor to replace manual piston movement, improving ergonomics and reducing force.

Process:

Press the main button to aspirate and dispense. They are ideal for repetitive pipetting tasks.

Positive Displacement Pipettes

Design:

• • Direct Contact: In positive displacement pipettes, the liquid directly contacts the piston. These pipettes are either dispensers (for single aliquots) or repeaters (for multiple aliquots of the same size).
  • Dispenser Tips: Tips for positive displacement pipettes are often called dispenser tips.

Use Cases:

• • Volatile Liquids: Positive displacement pipettes are ideal for pipetting volatile solutions that might escape air-displacement tips.
  • Viscous Solutions: They handle both aqueous and non-aqueous viscous solutions effectively.
  • Highly Accurate: Positive displacement pipettes provide precise volumes, especially when dealing with challenging samples.
  • Single-Use Applications: They’re suitable for applications where contamination risk must be minimized.

Application Examples:

• • Pipetting viscous or volatile liquids

How do Positive Displacement Pipettes work?

Working Principle:

They use disposable tips that directly displace the liquid. Ideal for viscous or volatile samples.

Process:

Aspirate the liquid using a disposable tip. These are suitable for challenging samples.