Skip to main content
Biology LibreTexts

8.5: Stain and analyze the agarose gel

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


    Wear disposable gloves when staining gels. Gloves are important when working with intercalating dyes, which are potential mutagens.

    1. Remove the gel from the apparatus and transfer the gel to a small tray. Cover the gel with deionized water. Add 5 μL of EtBr solution (10 mg/mL) to the tray. What is the approximate concentration of EtBr in the staining solution?
    2. Place the tray on a rocking platform and rock gently for 20-30 minutes.
    3. Drain the EtBr solution in to the appropriate waste container in the fume hood.
    4. Cover the gel with deionized water and rock gently for 1 minute.
    5. With a spatula, carefully place the gel on the transilluminator and close the cover to the Gel- Logic apparatus. (Drain the wash solution into the waste container.)
    6. Turn on the transilluminator light and photograph the gel according to the posted instructions. Turn off the transilluminator immediately after you photograph the gel. Save the picture and email a copy to yourself. (If no bands are apparent, the staining can be repeated for a longer period of time.)
    7. Open the door of the GelLogic apparatus. Use the spatula to transfer the gel to a waste con- tainer set up for EtBr-stained gels.
    8. Determine the approximate length of the DNA molecules in your samples by comparing their migration to that of the standards. Are the sizes consistent with your expectations?

    This page titled 8.5: Stain and analyze the agarose gel is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Clare M. O’Connor.

    • Was this article helpful?