Agarose gel electrophoresis is the most common way of separating and analyzing DNA.
Agarose is a polysaccharide, generally extracted from certain red seaweed. It is a linear polymer made up of the repeating unit of agarobiose, which is a disaccharide made up of D -galactose and 3,6-anhydro- L -galactopyranose.
Preparing 1% Agarose gel:
Gels are prepared in terms of percent’s: say 0.7%, 0.8%, 1%, or 2% are pretty common gel percentages of the gel you use depends on the fragment size you’re expecting and how good you need to separate the fragments.
As we are interested in making 1% gel : we need to take weigh 1 gram of agarose and dissolve it into 100ml of TAE or TBE buffer.
Contents are heated ( in a microwave oven) till the agarose dissolves completely and a transparent solution is observed.
This transparent solution is cooled five minutes (if you’re in a big rush you can run water over the surface of the flask to cool it down).
Next add ethidium bromide or any non toxic dye (DNA Dye Non-Toxic products) and pour on gel casting apparatus. After cooling the gel will be solidified and can be used for separating DNA samples.
These dyes can intercalates with DNA (when loaded on this gel) and makes it visible under UV light.
For preparing 2% gel click here