DNA GEL ELECTROPHORESIS

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amberdagp
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DNA GEL ELECTROPHORESIS

Post by amberdagp » Sat Mar 14, 2009 6:44 pm

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

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canalon
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Post by canalon » Mon Mar 16, 2009 8:45 pm

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.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

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Re: DNA GEL ELECTROPHORESIS

Post by amberdagp » Tue Mar 17, 2009 5:58 pm

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

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Post by amberdagp » Tue Mar 17, 2009 7:19 pm

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

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canalon
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Post by canalon » Wed Mar 18, 2009 1:23 am

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.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

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MrMistery
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Post by MrMistery » Wed Mar 18, 2009 1:39 pm

^ nice analogy patrick
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

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