2007-04-16 12:10:03 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Biology
DNA passes through a gel at different speeds depending on its size, how many kilobases (kb) long it is. If you are running fragments of unknown size a known marker is run at the same time. Marker DNA comes in sets referred to as ladders. To determine the unkown's molecular weight one looks at the nearest 'rung' and looks up its size. The manufacturer provides a map.
Depending on the range of DNA sizes gels of differing percentages may be needed to fine tune the results. A low percentage gel is used when very large pieces, like genomic DNA, is being run.
2007-04-16 12:43:10 · answer #1 · answered by gardengallivant 7 · 1⤊ 0⤋
The marker DNA serves to compare it to your strips of DNA, normally the manufacturer includes the actual base pairs within each strip of the marker DNA, it is pre-cut so they know exactly how many base pairs there are in each. This is so you can estimate the number of base pairs in your DNA.
2016-03-06 09:05:30 · answer #2 · answered by Andrea 1 · 0⤊ 0⤋
Well it matters what you're running.
Is the marker DNA being compared to the DNA that you ran?
So the purpose I guess would be to find matching segments, and combinations.
2007-04-16 12:14:03 · answer #3 · answered by h n 1 · 0⤊ 0⤋