Science Buddies: "Ask an Expert"

Hi ,
when i passed electricity through the gel electrophoresis chamber, copper colored bubbly froth like substance formed at the anode. I used stainless steel electrodes, and i think the problem is with them. will it interfere with the electrophoresis process? can you please explain it? Also will this experiment work with an actual DNA sample (made with DNA, glycerol and food coloring loading buffer)?

Thanks.

Hello,

I can't address the colored substance that you saw when doing your electrophoresis, but are you sure that there were no contaminants in the buffer or chamber that could cause this? There should be a moderate amount of bubbling when doing any kind of electrophoresis; this is normal. In my experience, it is just a white froth from the buffer used.

The stainless steel electrodes should be fine. To visualize DNA, you will need a stain such as ethidium bromide (EtBr), which binds DNA and fluoresces under UV light. You will not be able to see a DNA band without a stain. However, because of safety concerns of using EtBr, I do not think you can commercially purchase this. Only an academic research lab or university would have access. The inclusion of glycerol and loading buffer is fine, but note that the loading buffer will separate as a distinct band from the DNA in the electrophoresis and will NOT serve as an adequate method of "tracking" the exact location of the DNA in the gel.

Let us know if you have further questions. Best of luck!

-Pharma

Okay, so I got the experiment to work so far, and used methylene blue to stain the DNA. It worked, but only my spinach sample visualized in bands. I'm guessing this is because the other samples weren't dissolved properly into loading buffer, so I'm retrying. The problem is that the anode dissolved completely last time, so I need to get a new one. Will galvanized steel wire work?