I need help with this project “ Forensic Science: Building Your Own Tool for Identifying DNA”

[Blooop]

I can’t get it to work at all, I think I’ve done all the directions right and I’ve tried replacing the electrodes, batteries, food dye. I just can’t seem to get it to work, and really need some help/tips. I got the electrodes to bubble in the chamber and left my chamber alone for thirty minutes in the couple times I’ve re tried this project but my colors don’t seem to separate. I think I’m doing it correctly but if I could get advice on things I might be doing wrong or advice I’d appreciate the input.

[akulk]

Hi there!

Thank you for your question!

One possible reason for your problem may be incorrect electrode placement. Have you confirmed that you have connected the red lead with the positive electrode and the black lead with the negative electrode? If the electrodes are reversed – that is, the red lead connected to the negative electrode and the black lead connected to the positive electrode – the electric field will be reversed. Regardless of the reversed electric field, it is likely that the electrodes will still bubble – as you mentioned observing.

If the electrodes have been set up correctly, it is possible that the gel containing the food dye samples was oriented incorrectly. Are the wells of your gel closer to the negative electrode side? The samples should be moving from the negative electrode side toward the positive electrode. This is because the molecules of the food dye are negatively charged – so they will be attracted to the positive electrode, and repelled by the negative electrode.

Hope this helps you with your troubleshooting! If you notice any more problems, please let us know – we’d be happy to help!

Anika

[Blooop]

I think my electrodes are connected to the correct side and clips at least? Is there a certain size of plastic box I should use, and if size of it interferes at all? How long should I wait to see color separation, is it possible I just didn’t give it enough time?

[akulk]

Generally, the size of the plastic box should not affect the gel electrophoresis results – unless the size of the gel is substantially decreased because of box size. However, the timing of the run may very well impact the results – just as you suggested.

How long are you leaving your apparatus to run?