DNA GEL ELECTROPHORESIS

[amberdagp]

Hi can you please help me...
The question i have been asked in after doing my Electrophoresis practical is: measure how far each of the observable fragments move (mm), tabulate the data and constrct a fully labelled calibration curve of migration distance against log10 (fragment size)

Firstly, how do the measure the fragments, can anyone please tell me this very clearly as i do not get it, what parts do i need to measure and what i need to show in my table...

Thank you very much in advance
take care

[canalon]

You need to measure the distance between the wells and the observed bands. Tabulate
band -size -log10 fragment size -migration in mm
use the table to draw the curve.

[amberdagp]

Ok thank you by the way, to measure the lanes where the fragments are undistingushable, and all you can see is a big shaded area in the lane, how would you measure in mm the distance of migration? this is as i need to get the average distance of a lane where the fragments are not separate and are all bunched together

[amberdagp]

also why are base pair fragments different in number with haeIII in comparision to hindIII??

[canalon]

If your fragments are not separated, I can't do much. But you should measure to the front of the band. And different restiction enzyme have different cutting site, so likely different fragment size: think of divinding a book in fragments everytime a certain word appears, say "car" for one and "sleep" for the other, you would not expect the different fragments to be the same size. It is the same with restriction sites.

[MrMistery]

^ nice analogy patrick