What Is a Pipette?
A pipette is a common laboratory tool used to transport a measured volume of liquid with a high degree of accuracy. It is essentially a small tube, often made of glass or plastic, that uses suction to draw up and dispense liquids. Pipettes are fundamental in fields like chemistry, biology, and medicine where precise liquid handling is critical.
Section 2: Types of Pipettes
There are several types of pipettes, each designed for a specific purpose. Volumetric pipettes have a single graduation mark and are designed to deliver one specific, highly accurate volume (e.g., 25.00 mL). Graduated pipettes have markings along their length, allowing for the transfer of various measured volumes. Micropipettes are adjustable and used for transferring very small volumes, typically measured in microliters (µL).
Section 3: A Practical Example
Imagine a biologist preparing a sample for DNA analysis. They might use a micropipette to add exactly 10 microliters of an enzyme to a test tube containing DNA. The micropipette's precision is crucial because even a tiny error in volume could ruin the experiment. For safety and accuracy, a pipette bulb or a mechanical pipetting aid is always used to draw liquid into the pipette, never the mouth.
Section 4: Importance in Science
The importance of the pipette lies in its ability to ensure reproducibility and accuracy in scientific experiments. In quantitative analysis, pharmaceutical formulation, and diagnostic testing, results depend on the precise ratio of ingredients. Pipettes allow scientists to control these ratios meticulously, leading to reliable and valid experimental outcomes.