Restriction Mapping

[bioneedhelp]

Hi, I have a HUGE test on DNA and I was wondring if anyone can explain exactly what an agar is or does (electrophoresis i think).

[canalon]

Hi, I have a HUGE test on DNA and I was wondring if anyone can explain exactly what an agar is or does (electrophoresis i think).

You are probably talking about electrophoresis in agarose. It is a method used to discriminate DNA molecules based on size (generally length, but sometimes other structures may be important too)
This method is used to discriminate DNA molecule by size. Basically Agarose is used in concentrations ranging around 1% to prepare a gel (think of it as a giant net for which the size of the holes depends on the concentration of the agarose). DNA being charged move in an electric current. If you put DNA in the gel and let an electric current go through the gel, the DNA will move through it, and the speed of the movement will depend on both the tension (the higher, the faster) and the size of the DNA molecules. The last one because DNA has to move through the holes of the gels. The smaller the DNA molecule, the easiest to move, hence the faster to go through the gel. After a while when you detect DNA it will show different bands corresponding to the size of the different DNA in the original mix.

HTH

Patrick

[bioneedhelp]

Thanks for the help! It definitly cleared some confusion!