1. What is a pipette tip? Pipette tips are cone-shaped, hollow plastic objects that fit at the end of a pipette to cleanly aspirate (aspirate) and dispense small amounts of liquid. The pipette tips work with the pipette to form an air-tight seal so scientists can transfer accurate volumes of liquid from one container to another. They are typically made of polypropylene, are single-use, and are available in a variety of sizes and volumes to suit specific applications and pipettes. Since the pipette tip is in direct contact with the target sample, it can significantly affect the experimental results. Discarding pipette tips between each experimental step helps prevent cross-contamination.

2. What is pipette tip sterility? Pipette tips are sterile meaning they are free of bacteria or any viable microorganisms or spores, but without additional qualifications (such as BioClean Ultra), they may still contain contaminants that may affect experimental results. Uncertified pipette tips unknowingly introduce organic and non-organic contaminants into liquid samples, potentially affecting reaction conditions and experimental results. Contaminants can cause adverse and unpredictable effects on enzyme activity and lifetime, molecular interactions, spectrophotometric and chromatographic analyses, and more.

3. What is BioClean Ultra? BioClean means all Rainin air displacement tips are tested to extremely high standards and found to be free of detectable amounts of specific biological contaminants such as DNA (human and bacterial), RNase, DNase, endotoxins, proteins, proteases, ATP and PCR inhibitors. BioClean Ultra pipette tips are manufactured in a fully automated Class 100,000 clean room facility. To ensure absolute purity, no additives or dyes are used and ISO 9001 compliant manufacturing procedures are followed to eliminate all external sources of contamination. From raw material selection to clean production and automated packaging, Rainin BioClean Ultra pipette tips are pure and completely safe.

4. Why use capillary and piston pipette tips? Capillary and piston pipette tips, also known as syringe tips, are suitable for external piston pipettes. External plunger pipettes and tips are recommended over air-displacement pipettes (which are more common) for handling liquids that are viscous, dense, or otherwise physically difficult to move in and out of the pipette. Why? Because the air inside air-displacement pipettes stretches and compresses, this can lead to inaccurate measurements when working with viscous liquids. Capillary and piston pipette tips are filled with a piston that extends down into the opening of the tip, virtually removing the air between the liquid and the end of the piston. Because there is no air inside, capillary and piston syringe tips provide excellent precision, repeatability, and control of viscous liquids. They are also recommended when pipetting volatile organic liquids and low surface tension liquids.

5. What are the different pipette tip sizes? Pipette tips are available in a variety of sizes to help meet user needs. The smallest volume pipette tip used in a typical laboratory is 10 microliters, while the maximum capacity is 20 ml. Pipette tips are tapered conical containers, usually made of polypropylene, whose internal volumes are calibrated to aspirate, hold, and transfer different volumes of liquid during a variety of analytical procedures. Rainin LTS sizes and filter options: 20 μL filtered and unfiltered, 250 μL filtered/200 μL filtered, 300 μL filtered and unfiltered, 1000 μL filtered and unfiltered, and 1200 μL filtered and unfiltered. Rainin UNV (universal) pipette tip sizes and filter options: 10 μL filtered and unfiltered, 20 μL filtered, 100 μL filtered, 250 unfiltered/200 μL filtered, 300 μL filtered and unfiltered, and 1000 μL filtered and unfiltered.

6. When should pipette tips be replaced? Replacing pipette tips depends on the individual assay method. To help eliminate the risk of cross-contamination, use fresh tips after each aspiration/dispensing cycle.

7. Can pipette tips be washed and reused? Cleaning and reusing pipette tips is not recommended. Tip surface properties can change upon wetting, especially with organic liquids or liquids of different compositions. This changes liquid retention and therefore the accuracy and precision of pipetting. Additionally, organic liquids or components can spread to the polypropylene surface and contaminate subsequent liquids that enter the interior of the tip.