Reading the electrophoresis gel for the enzyme Hind III and Bgl II

Which lane is the standard?

What are your DNA molecular weight markers, are they 23kb, 9.4kb, 6.6kb, etc...

Yes, my standard marker are those sizes. And the standard marker is Hind III. My experimental sample would be Bgl II.

It looks like you have three prominent bands, good job. Now all you have to do is extrapolate the distance by plotting the standard markers on a graph. On a piece of semi-log graph paper, plot the log of the molecular weight each standard vs. distance traveled from the well (based on measurements made from the picture of the gel). Draw a line connecting the points (although the line won't be linear). From this you should be able to determine the molecular size of the linearized plasmid.

If you have questions on how to do this, reply back, I will upload a step-by-step tutorial.

Actually, I was asking how to read it. For the HindIII I mean. It would be great if anybody could show me this.

Hi Linda, the further down it travels, the lighter the band is, whereas the heavier it is, it will be closest to the top.

can you give me an example on how the first one is read so I have an idea how.

Sure, for HindIII, you have 7 bands, with the 7th one being closest to the bottom. You said your experimental sample is Bgl III. Now because the marker has 7 bands:

23kb
9.4kb
6.6kb
4.4kb
2.3kb
2.0kb
0.6kb

The one closest to the bottom is: 0.6 kb. If you look at BgIII, you have one very close to the bottom one as well, so we can extrapolate and say it too is 0.6 kb. The band is very light, but it's still visible. Do you see it Now look at the 5th band of the HindIII marker (2.3kb) [Start counting from the top]. In comparison to the 4th band of the BgIII (second band closest to the bottom), it's very similar in distance, so we can say it's the same.

Make sense Lind?