1. National Centre for Biotechnology Education www.ncbe.reading.ac.uk Gel electrophoresis Protein power! Copyright © Dean Madden, 2010

2. The negatively-charged proteins move through the gel towards the positive electrode The gel contain minute holes, so it acts like a sieve. Small proteins move quickly; larger proteins follow on behind. Positive electrodeNegative electrode

3. Copyright © Dean Madden, 2010 Fit a tip firmly onto a syringe, using some tubing as an adapter Use this syringe and tip to transfer your protein samples

4. Copyright © Dean Madden, 2010 Add 0.5 mL of blue marker dye to each protein sample About 0.5 mL Protein sample Label the tube

5. Copyright © Dean Madden, 2010 Float the tubes in boiling water for three minutes, then store them on ice OPTIONAL STEP

6. Copyright © Dean Madden, 2010 Frosted panel on this side Molten agarose (3%) 55–60 °C

7. Copyright © Dean Madden, 2010 Cut two electrodes Carbon fibre tissue 42 mm 22 mm

8. Copyright © Dean Madden, 2010

9. Use a fresh tip for each sample you load into the gel Label the end of the tank to show the contents of each well Black card under the tank reveals the wells for loading 2–3 mm depth of buffer over the gel

10. Copyright © Dean Madden, 2010 Electrodes

11. Copyright © Dean Madden, 2010 Direction of protein movement Place a comb over the tank to reduce evaporation

12. Copyright © Dean Madden, 2010 Leave the stain on for 60 minutes Coomassie blue stain

13. Copyright © Dean Madden, 2010 The Coomassie blue stain soaks into the gel and reveals the proteins

14. Copyright © Dean Madden, 2010 WellsMarker dye Protein bands