A pipetter, also known as a pipette, is a laboratory tool used to measure and transfer precise volumes of liquid. It is essential in various scientific fields, including biology, chemistry, and medicine, where accurate liquid handling is crucial. Pipetters come in different types, such as manual, electronic, single-channel, and multi-channel, each designed for specific applications. The primary function of a pipetter is to ensure the accurate and reproducible transfer of liquids, which is vital for experimental consistency and reliability. In research and clinical laboratories, pipetters are used for tasks such as preparing solutions, diluting samples, and transferring reagents. They are indispensable in techniques like polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and cell culture, where precise liquid handling can significantly impact results. Pipetters operate by creating a vacuum to draw liquid into a disposable tip, which is then dispensed into another container. The volume of liquid transferred can be adjusted, allowing for flexibility in experimental design. Modern pipetters often feature ergonomic designs to reduce user fatigue and digital displays for enhanced accuracy. In summary, a pipetter is a critical tool in laboratories for the precise measurement and transfer of liquids, ensuring the accuracy and reliability of scientific experiments and procedures.

To use a pipette correctly, follow these steps: 1. **Select the Right Pipette and Tip**: Choose a pipette that matches the volume you need to transfer. Attach a compatible tip by firmly pressing the pipette into the tip box and twisting slightly to ensure a secure fit. 2. **Set the Volume**: Adjust the volume by turning the dial on the pipette. Ensure the volume is within the pipette's range to maintain accuracy. 3. **Pre-Rinse the Tip**: Aspirate and dispense the liquid a few times to coat the inside of the tip, which helps improve accuracy and precision. 4. **Aspirate the Liquid**: Press the plunger to the first stop, immerse the tip into the liquid (2-3 mm below the surface), and slowly release the plunger to aspirate the liquid. Avoid air bubbles by keeping the pipette vertical and moving the plunger smoothly. 5. **Dispense the Liquid**: Touch the tip to the side of the receiving vessel to prevent splashing. Press the plunger to the first stop to dispense the liquid, then press to the second stop to expel any remaining liquid. Withdraw the tip while keeping the plunger depressed. 6. **Dispose of the Tip**: Eject the used tip into a waste container by pressing the tip ejector button. Use a new tip for each different liquid to avoid cross-contamination. 7. **Maintain the Pipette**: Regularly calibrate and clean the pipette according to the manufacturer's instructions to ensure accuracy and longevity. By following these steps, you ensure precise and accurate liquid handling, which is crucial for reliable experimental results.

Pipetters are essential laboratory tools used for transferring precise volumes of liquid. They come in various types, each suited for specific applications: 1. **Air Displacement Pipettes**: These are the most common type, using a piston to create a vacuum that draws liquid into a disposable tip. They are ideal for aqueous solutions and are available in single-channel and multi-channel versions. 2. **Positive Displacement Pipettes**: Unlike air displacement pipettes, these have a piston that directly contacts the liquid, making them suitable for viscous, volatile, or corrosive substances. They minimize the risk of contamination and evaporation. 3. **Electronic Pipettes**: These offer motorized operation for enhanced precision and ease of use. They can be programmed for various functions, such as mixing or sequential dispensing, and reduce user fatigue. 4. **Manual Pipettes**: Operated by hand, these are cost-effective and simple to use. They require manual adjustment of the volume and are suitable for general laboratory tasks. 5. **Multichannel Pipettes**: Designed for high-throughput applications, these pipettes have multiple channels (usually 8 or 12) for simultaneous dispensing into microplate wells, increasing efficiency in tasks like ELISA or PCR. 6. **Repeater Pipettes**: These allow for the dispensing of multiple aliquots of the same volume from a single aspiration, ideal for repetitive tasks and reducing hand strain. 7. **Serological Pipettes**: Used for transferring larger volumes, these are typically made of glass or plastic and require a pipette controller or bulb for operation. 8. **Volumetric Pipettes**: Known for high accuracy, these are used for transferring a single, specific volume of liquid and are often employed in analytical chemistry. Each type of pipetter is designed to meet specific laboratory needs, ensuring accuracy, efficiency, and safety in liquid handling tasks.

To calibrate a pipette, follow these steps: 1. **Preparation**: Ensure the pipette is clean and in good working condition. Gather necessary materials: distilled water, a balance with at least 0.01 mg precision, a container, and a thermometer. 2. **Environmental Conditions**: Perform calibration in a controlled environment, ideally at 20-25°C and 50-75% humidity. 3. **Balance Calibration**: Calibrate the balance using standard weights to ensure accuracy. 4. **Water Temperature**: Measure the temperature of the distilled water, as water density varies with temperature, affecting volume calculations. 5. **Volume Setting**: Set the pipette to the desired volume. For variable volume pipettes, calibrate at the minimum, maximum, and a mid-range setting. 6. **Weighing**: Tare the balance with the container. Aspirate the set volume of water with the pipette and dispense it into the container. Record the weight. 7. **Repeat Measurements**: Perform at least 10 measurements for each volume setting to ensure reliability. 8. **Calculate Mean and Standard Deviation**: Determine the mean weight of the dispensed water. Calculate the standard deviation to assess precision. 9. **Convert Weight to Volume**: Use the water density (from a density table based on the measured temperature) to convert the mean weight to volume. 10. **Accuracy and Precision Assessment**: Compare the calculated volume to the set volume. Calculate the percentage error for accuracy and the coefficient of variation for precision. 11. **Adjustment**: If the pipette is out of specification, adjust it according to the manufacturer’s instructions and repeat the calibration process. 12. **Documentation**: Record all data, calculations, and any adjustments made for future reference and compliance. 13. **Regular Calibration**: Schedule regular calibration checks based on usage frequency and manufacturer recommendations.

To clean and maintain a pipetter, follow these steps: 1. **Disassembly**: Carefully disassemble the pipetter according to the manufacturer's instructions. Typically, this involves removing the tip cone, piston, and other detachable parts. 2. **Cleaning**: - **External Cleaning**: Wipe the exterior with a lint-free cloth dampened with a mild detergent or 70% ethanol solution. - **Internal Cleaning**: Soak the disassembled parts (except the piston) in a mild detergent solution. Use a soft brush to remove any residue. Rinse thoroughly with distilled water and allow to air dry. - **Piston Cleaning**: Wipe the piston with a lint-free cloth dampened with 70% ethanol. Avoid soaking the piston to prevent damage. 3. **Decontamination**: If the pipetter has been exposed to biohazardous materials, decontaminate using an appropriate disinfectant, such as 10% bleach solution, followed by thorough rinsing with distilled water. 4. **Lubrication**: Apply a small amount of lubricant (as recommended by the manufacturer) to the piston and O-rings to ensure smooth operation. Avoid over-lubrication. 5. **Reassembly**: Carefully reassemble the pipetter, ensuring all parts are securely in place. Follow the manufacturer's guidelines to avoid damaging the components. 6. **Calibration Check**: After cleaning, check the calibration of the pipetter. Use a balance to verify the accuracy of the dispensed volume. Adjust the calibration if necessary, following the manufacturer's instructions. 7. **Regular Maintenance**: Schedule regular maintenance checks, including cleaning, lubrication, and calibration, to ensure optimal performance. Frequency depends on usage and manufacturer recommendations. 8. **Storage**: Store the pipetter vertically on a stand to prevent contamination and damage. Avoid laying it flat or storing it with a tip attached. By following these steps, you can ensure the longevity and accuracy of your pipetter.

A pipetter, often referred to as a micropipette, offers several advantages over a transfer pipette, particularly in laboratory settings where precision and accuracy are crucial. 1. **Precision and Accuracy**: Pipetters are designed to deliver precise and accurate volumes of liquid, often with an error margin as low as ±1%. This is essential in experiments where exact measurements are critical. 2. **Volume Control**: Pipetters allow for adjustable volume settings, enabling the user to dispense a wide range of volumes with a single instrument. This flexibility is not available with transfer pipettes, which are typically fixed-volume. 3. **Reproducibility**: The consistent mechanism of pipetters ensures that the same volume is dispensed every time, enhancing the reproducibility of experiments. 4. **Ease of Use**: Ergonomically designed, pipetters reduce hand strain and are easier to use for repetitive tasks compared to the manual squeezing required for transfer pipettes. 5. **Contamination Prevention**: Pipetters often use disposable tips, which can be changed between samples to prevent cross-contamination. Transfer pipettes, being reusable, pose a higher risk of contamination unless thoroughly cleaned. 6. **Speed and Efficiency**: The quick and efficient operation of pipetters allows for faster processing of multiple samples, increasing laboratory throughput. 7. **Versatility**: Pipetters can be used with a variety of liquids, including viscous or volatile substances, without compromising performance, unlike transfer pipettes which may not handle such substances well. 8. **Safety**: The design of pipetters minimizes the risk of exposure to hazardous chemicals, as the liquid is contained within the disposable tip. Overall, pipetters provide a more reliable, efficient, and user-friendly solution for liquid handling in scientific research and clinical diagnostics compared to transfer pipettes.

To choose the right pipette tips for a pipetter, consider the following factors: 1. **Compatibility**: Ensure the tips are compatible with your pipette brand and model. Manufacturers often provide compatibility charts. 2. **Volume Range**: Match the tip size with the pipette's volume range. Using tips that are too large or small can affect accuracy and precision. 3. **Material**: Most tips are made from polypropylene, but consider low-retention tips for viscous or sticky liquids to minimize sample loss. 4. **Sterility**: For applications requiring sterility, such as cell culture or molecular biology, use sterile, individually wrapped, or racked tips. 5. **Filter Tips**: Use filter tips to prevent aerosol contamination and protect the pipette from sample contamination, especially in sensitive applications like PCR. 6. **Tip Design**: Choose between standard, extended, or wide-bore tips based on the application. Wide-bore tips are ideal for handling cells or viscous liquids. 7. **Quality and Certification**: Opt for tips that are certified free of DNase, RNase, and pyrogens for sensitive applications. High-quality tips ensure better accuracy and reproducibility. 8. **Ergonomics**: Consider tips that provide a good seal with minimal force to reduce hand strain during repetitive pipetting. 9. **Cost**: Balance cost with quality. While cheaper tips may seem economical, they can compromise results and lead to higher long-term costs. 10. **Environmental Impact**: Consider eco-friendly options, such as refill systems or tips made from recycled materials, to reduce plastic waste. By evaluating these factors, you can select pipette tips that enhance performance, ensure accuracy, and meet the specific needs of your laboratory applications.