The classification of pipette tips is mainly based on functional design. Common types include standard tips, filter tips, low adsorption tips, gel tips, extended tips, large-capacity tips and automated tips. As the most widely used type, standard tips are suitable for almost all conventional pipetting operations, and their economy makes them a basic choice for laboratories. Filter tips have built-in sand core filters to effectively prevent aerosol contamination and liquid reflux, especially for experimental scenarios such as molecular biology and cytology that are sensitive to cross-contamination. Low adsorption tips significantly reduce liquid residues through surface hydrophobic treatment, especially for precision experiments such as DNA and RNA, and recovery operations of high-value samples.

Gel tips are designed for gel electrophoresis experiments. Their slender extensions can penetrate deep into the gel sample holes to prevent sample spillage. Extended tips solve the problem of sampling from deep containers such as conical tubes and tall reagent bottles by increasing their length, while reducing the risk of cross-contamination. Large-capacity tips are designed for large-volume liquid transfer. They are designed with an extended and wide-mouth design to achieve one-step operation and significantly improve pipetting efficiency. Automated tips are designed for high-throughput experiments. Combined with the liquid level detection function of the workstation, they ensure the accuracy of pipetting and liberate the manpower of experimenters.

The material of the pipette tip directly determines its chemical stability, high temperature resistance and mechanical properties. Polypropylene (PP), as the mainstream material, is widely used in most laboratory operations due to its good chemical stability and corrosion resistance. However, for experiments that require high temperature resistance or highly corrosive environments, polyvinyl fluoride (PFA) and polytetrafluoroethylene (PTFE) tips are more preferred. For example, in experiments involving strong acids, strong bases or organic solvents, PFA and PTFE tips can avoid the interference of material extracts on experimental results.

The purity of the material is also crucial. High-quality tips usually use natural polypropylene, while cheap products may use recycled plastics, resulting in excessive extracts. Dissolution will not only affect the accuracy of experimental results, but may also have toxic effects on experiments such as cell culture and enzyme activity. Therefore, when choosing a pipette tip, it is necessary to focus on the purity of the material and the use of additives.

The capacity selection of the pipette tip must be strictly matched with the range of the pipette tips. Different types of pipettes have specific adaptation ranges. For example, a 10μL tip is suitable for 1-10μL and intermediate range pipettes, while a 1000μL tip is suitable for 100-1000μL pipettes. Improper capacity adaptation will lead to deviation in the pipette volume and even damage the pipette. For example, when using a 200μL tip with a 5-50μL pipette, the tip may get stuck in the pipette, causing operational failure.

The setting of the pipette volume must follow the "35%-100% range" principle, that is, the actual pipette volume should be between 35% and 100% of the pipette range. This range ensures the best pipetting accuracy and avoids errors caused by too small or too large a range. For example, when pipetting 10μL of liquid, it is more accurate to choose a 10μL tip than a 100μL tip, because the latter has significantly reduced accuracy at low ranges.

The sealing between the tip and the pipette tips directly affects the accuracy of pipetting. High-quality tips must have good concentricity and taper to ensure a tight fit with the pipette. Insufficient concentricity can cause leakage or bubbles during pipetting, while taper deviation may cause unstable pipetting volume. For example, if the center of the nozzle of the tip is inconsistent with the center of the connection with the pipette, the liquid may seep out of the gap during pipetting, resulting in deviation in experimental results.

The sealing test can be verified by actual operation: after pipetting, suspend the tip vertically above the liquid surface to observe whether there is any liquid dripping. If dripping occurs, it means that the sealing is insufficient and the tip needs to be replaced. In addition, the surface smoothness of the tip must also meet the standard to avoid liquid residue due to flow marks or burrs.

The correct use and maintenance of the pipette tip are equally important. When installing, make sure that the pipette tip is inserted vertically into the pipette to avoid deformation caused by strong impact. During the pipetting process, the tip of the pipette tip must always be immersed below the liquid surface to prevent errors caused by suction. After pipetting, the pipette tip should be discarded in a dedicated container immediately to avoid cross contamination.

Routine maintenance of the  pipette tipsrequires regular cleaning and calibration. Use 70% alcohol solution to wipe the surface of the pipette and avoid using corrosive solvents. Perform professional calibration 1-2 times a year to ensure that the accuracy of the pipette meets the standard. In addition, the pipette must be kept in an upright position when stored to prevent the liquid in the pipette tip from flowing back and corroding the piston.