Southern blotting
Southern blotting is when you isolate a particular gene.
First you have to do electrophoresis on with the DNA. You use restriction enzymes to break up the DNA and the run the gel using agarose. The smallest fragments ith travel the furthest. Place nitrocellulous filter on plate to pick up phages from each plaque. Left with single stranded DNA. Hybridise with labelled probe. Denature the DNA using NaOH. Left with single stranded DNA. Hybridise with labelled probe. Perform autoradiography. Signal appears over phage DNA that is complementary to probe. Cut out signal area to obtain DNA.