Hi all,

I am currently studying biomedicine in my first year and would like a help with the following question regarding Restriction Digestion and Electrophoresis of DNA.

   Suppose you have two 1000 bp sequences of DNA (call them “sample 1” and “sample 2”) which are identical in sequence apart from a single base pair that has been mutated in sample 2. Both sequences normally have two restriction sites for a particular restriction enzyme, one at nucleotide 300 and the other at nucleotide 700, but in sample 2, the point mutation has altered the first restriction site so that it is no longer recognised by the restriction enzyme.
Explain how you would use restriction digestion and agarose gel electrophoresis to demonstrate the differences between the two DNA samples, specifically describing the predicted pattern of fragments and indicating their sizes.

many thanks.

Sultan