What does the brightness of the band in an electrophoresis gel indicate?

Question

I used PCR to amplify my samples and then ran it on a 3% agarose gel using electrophoresis. I think that the brightness of the band indicates the quantity and quality of the DNA, but i need some credible sources to confirm that (medical journals, etc). where can i find sources that say what the brightness of the band indicates? thanks in advance.

Answer 1

your teacher. google "gel electrophoresis." your textbook. etc.

the brighter the band, the more DNA is concentrated at that spot. the quality really has nothing to do with it. when you run the gel, the longer fragments stay up near the wells (because they are larger and bulkier and can't move through the gel as well.) and the shorter fragments move towards the other end (because they are smaller and can more easily scoot their way through the gel to the positive charged end.)

and maybe try pubmed and nih. read some articles about gel electrophoresis (people use it a lot) and see what they say it implies to have a brighter band. good luck!