Pipetování, also known as pipetting, is a fundamental technique in laboratories worldwide, used in both research and clinical applications.
This precise manipulation of liquids is essential for a wide range of experiments, from analytical chemistry to molecular biology.
In this article, we will delve deeply into the art and science of pipetting, highlighting its importance, the types of pipettes, best practices, and technological advances that have revolutionized this technique.
◍ What is pipetování?
Pipetování is a laboratory technique used to accurately transfer liquid volumes from one place to another using an instrument called a pipette.
This skill is crucial to ensure the accuracy of experimental results and for drug development, genetic research, disease diagnosis, and much more.
Precision in pipetting directly affects the quality and reliability of collected data, emphasizing the importance of this technique in the scientific realm.
◍ Types of Pipettes
There are several types of pipettes designed to meet the specific needs of different procedures. The main types include:
- Volumetric Pipettes: Ideal for measuring a fixed volume of liquid with extremely high precision. They are used when measurement accuracy is critical.
- Graduated Pipettes: Allow the transfer of variable volumes of liquids. Their graduation allows adjusting the volume as needed.
- Automatic Pipettes: Have revolutionized pipetting by allowing quick and accurate measurements of variable volumes, in addition to reducing user fatigue. These pipettes can be single-channel or multi-channel, facilitating work with multiple samples simultaneously.
Each type of pipette has its own advantages and specific applications, allowing researchers to choose the most suitable tool for their experiments.
◍ How to Pipette Correctly?
The pipetování process, or pipetting, is essential in the laboratory to ensure precision and accuracy in liquid transfer.
Below are the fundamental steps to perform effective and correct pipetting:
- Selection of the Right Pipette: The first step is to choose the most suitable pipette for the volume of liquid that needs to be transferred. Depending on the required precision and volume, you can opt for a volumetric, graduated, or automatic pipette.
- Verification and Calibration: Before starting, it is important to ensure that the pipette is calibrated correctly to avoid measurement errors.
- Pipette Preparation: Attach the appropriate pipette tip, ensuring it fits perfectly to avoid leaks or contamination. For volatile or viscous liquids, specific preparation techniques may be required.
- Liquid Aspiration: With the pipette in a vertical position, immerse the tip into the liquid to an appropriate depth. Slowly aspirate the liquid to the desired volume, avoiding bubble formation.
- Volume Verification: Ensure that the liquid level is at the correct mark. For graduated pipettes, adjust the volume if necessary.
- Liquid Transfer: Transfer the pipette to the destination container, keeping it in a vertical position to avoid spills. Dispense the liquid slowly, touching the container wall with the tip to ensure complete transfer.
- Residue Release: For some techniques, especially with volumetric pipettes, it is important to let the last drop drip without blowing or forcing the remaining liquid.
- Cleaning and Maintenance: After use, the pipette and tips should be properly cleaned following specific protocols for each type of handled liquid.
This carefully performed process ensures precision and reproducibility in pipetting, fundamental pillars for obtaining reliable results in any laboratory experiment or analysis.
◍ Best Practices in Pipetting
To ensure precision and reproducibility in pipetting, it is essential to follow a set of best practices:
- Regular Calibration: Pipettes should be calibrated periodically to ensure their accuracy. This calibration should be performed by qualified personnel or through specialized services.
- Correct Use of Tips: Always use compatible and quality pipette tips. This minimizes the risk of cross-contamination and ensures accuracy in liquid transfer.
- Appropriate Technique: Developing a consistent pipetting technique is crucial. This includes how to hold the pipette, the speed of aspiration and dispensing, and handling liquids of different viscosities.
- Preventive Maintenance: Regular maintenance prevents precision problems and extends the life of pipettes. This includes cleaning, changing seals and gaskets, and adjusting mechanical parts.
◍ Technological Advances
Technology has played a crucial role in the evolution of pipettes, improving both precision and efficiency. Advances include:
- Electronic Pipettes: Offer greater precision and reproducibility, allow programming of volumes and pipetting sequences, and reduce user fatigue.
- Automated Pipetting Systems: Enable automation of pipetting processes, which is especially useful in laboratories with high sample volumes. These systems can handle a wide range of volumes with exceptional precision and reproducibility.
- Software Applications: There are software designed to improve traceability and data management in pipetting, allowing detailed tracking of handled volumes, pipette calibration, and compliance with laboratory protocols.
Pipetting is more than just a laboratory task; it is a technique that requires precision, attention to detail, and a deep understanding of its impact on research and diagnosis.
The continuous evolution of pipetting tools and techniques underscores its importance in advancing science and medicine, ensuring that scientists can continue to rely on this essential methodology to obtain accurate and reproducible results.