micropipettes

Micropipettes are precision instruments used to measure and transfer very small volumes of liquids. They are hand-operated devices that draw liquid into a disposable tip and then dispense it with controlled accuracy, making them essential in biology, chemistry, and clinical laboratories.

Most micropipettes operate on air-displacement principles. A volume-adjustment dial sets a nominal volume. Pressing the plunger to the first stop aspirates liquid into the tip; pressing to the second stop dispenses the full volume. Positive-displacement pipettes, by contrast, use a disposable piston in contact with the liquid and are used for viscous, volatile, or foamy samples. Multi-channel versions allow simultaneous transfer into several wells, improving throughput.

Common configurations include single-channel models with ranges such as roughly 0.5–10 μL (P10), 2–20 μL (P20), 20–200 μL (P200), and 100–1000 μL (P1000); eight-channel variants are common for microplates. Tips are disposable and must be compatible with the pipette brand and model. Sterile or filtered tips reduce contamination and aerosol formation.

Calibration and maintenance are essential for accuracy. Pipettes should be calibrated regularly according to standards such as ISO 8655, with checks of accuracy and precision across the stated volume range. Routine care includes cleaning, inspecting seals and o-rings, using manufacturer-approved lubricants, and replacing worn parts. Proper tip handling and regular technique review help minimize systematic error.

Best practices include pre-wetting tips, holding the pipette vertically, delivering with a smooth, consistent motion, and avoiding bubbles. Micropipettes come in single- and multi-channel formats and are foundational tools for tasks from PCR setup to ELISAs and DNA quantification.