2007-01-11 23:16:20 · 2 answers · asked by amy t 1 in Science & Mathematics ➔ Biology
To determine the length of a DNA-fragment, you make an electrophoresis. The fragment an fragments of known length are placed in an agarose-gel which is under electric voltage. The DNA will move towards the positive pole, as it is negatively charged. You can then read the lenght of the fragment by comparing it to the fragments of known length.
Check the source for a picture. On the left and right, you can see the fragments of known length (ladder).
This method doesn't work for large fragments (more than a few 100 bp). For very small fragments another variant is frequently used. It works with acrylamide and on thinner layers, allowing better resolution. However it is more toxic and complicated.
2007-01-12 05:17:59 · answer #1 · answered by Dr. Zaius 4 · 0⤊ 0⤋
theres about 6 feet of dna in each cell
2007-01-12 07:26:31 · answer #2 · answered by Alex P 2 · 0⤊ 0⤋