TECHNIQUES LAB C-1:
CASTING & LOADING AN AGAROSE GEL
- Record your answers to questions a-c on the drawing of the electrophoresis gel box below.
- Label the gel, gel tray, and gel tray gates.
- Draw a line to show the desired buffer level. Label the line "buffer level".
- Use a large dot to show the loading dye placement. Label the dot "loading dye".
- Why should the agarose gel be left undisturbed while it is solidifying?
- Why do the gates need to be lowered before you put the gel into the gel box?
- What is the purpose of adding buffer before removing the comb?
- When must you consult with others who are using the same power supply ? Why is this consultation important?
- Record the location of the loading dye(s)* on the diagrams
below (BOTH the top and side views)
- Label the positive and negative ends of the gel in Figures A and B.
- Why would you want the end of the gel with the wells to be closer to the negative (cathode) end of the gel box?
- Explain why the dyes move toward the postive (anode) end of the gel.
*Note: Two dyes were combined to form "loading dye". One of these dyes moves faster than the small pieces of DNA, the other moves more slowly than the largest pieces of DNA.
- In this activity, DNA was not mixed with this loading dye. However, it will be when we need to separate fragments of DNA. Mark the "Fig. B Gel: After Electrophoresis" drawing (above) to show where you would expect to find DNA.