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Making a Genomic Library of DNA

How to find a needle in a haystack , or how to get the 10,000 base pairs you need out of the 10 billion base pairs you don't!

How do you cut the gene you need out of all the genetic material available in a cells nucleus?

In this method we take the shotgun approach, blasting the whole nucleus apart and searching through all the fragments in the hope of finding our required DNA piece.

1. Firstly cut up all of the Donors DNA with special "enzyme scissors" to make lots of different sized fragments or strands of DNA.

Restriction Endonucleases are the "scissors" used to cut up the DNA. These enzymes are made naturally by bacteria so they can eat and destroy any invading viral DNA.


The restriction enzymes cut the DNA at specific base sequences called PALINDROMES.


They can either cut to make Blunt ends :-


Or Sticky ends :-


2. Then search through all the fragments to Find the piece you want