Skip to main content
Chemistry LibreTexts

Appendix A: Operation of Eppendorf Adjustable Pipettes

  • Page ID
    78037
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    A1. Volume Setting

    The volume is adjusted by pressing down the lateral catch and turning the control button at the same time.

    It is advisable to carry out volume setting from the higher down to the lower value. i.e. first go above the desired volume and then return to the lower value.

    A2. Pipette tips

    Typically the color of the control button will correspond to the color of the eppendorf tip or tip rack. For the best precision and accuracy, pre-wet all new tips by aspirating and dispensing liquid 2-3 times before pipetting.

    A3. Aspirating liquid

    • Attach suitable pipette tip to the pipette firmly.
    • Press down the control button to the first stop (measuring stroke).
    • Immerse the pipette tip vertically ~3 mm into the liquid.
    • Allow the control button to slide back slowly.
    • Pull the tip out of the liquid slowly.
    • To remove any remaining droplets, dab with non-fibrous cellulose material, ensuring that liquid does not come out of the tip. You can also dab on the side of the beaker containing the liquid you are pipetting.

    A4. Dispensing liquid

    • Hold the tip at an angle against the inside wall of the tube/flask.
    • Press down the control button slowly to the first stop (measuring stroke) and wait until the liquid stops flowing.
    • Press down the control button to the second stop (blow-out) until the tip is completely empty.
    • Hold down the control button and pull the tip out of the inner wall of the tube/flask.
    • Allow the control button to slide back slowly.
    • Tip is ejected by pressing the control button to the final stop.

    Do not lay down the pipette when a filled pipette tip is attached as this may result in liquid entering the pipette.

    A5. Verification of pipette

    You can verify that the pipette is performing accurately by dispensing nanopure water from a prewetted tip into a tared flask or tube onto an analytical balance. Typically, one might test full volume and ½ volume, e.g. 500 and 1000 μL for a 1000 μL pipette.

    Convert the mass to volume by dividing by the density at room temperature. For example, the density of water is 0.9982 mg/μL at 20°C. This number is the volume actually delivered by the pipette. Determine the error relative to the set value. Repeat a few times to verify that the pipette is accurately delivering water. If not, consult your instructor.


    This page titled Appendix A: Operation of Eppendorf Adjustable Pipettes is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Contributor.