• Genetic engineering involves changing the genetic material in an organism to alter its traits or products• A recombinant DNA molecule contains DNA fragments spliced together from 2 or more organisms
Stages of cloning experiment Elements: Vectors Restriction enzymes Mechanism in joining the fragments Selection or detection of successful cloning Gene library
1. Joining DNA segment Vector 2. Providing milieu that allows propagationClones
1. Remove bacterial DNA (plasmid).2. Cut the Bacterial DNA with “restriction enzymes”.3. Cut the DNA from another organism with “restriction enzymes”.4. Combine the cut pieces of DNA together with another enzyme and insert them into bacteria.5. Reproduce the recombinant bacteria.6. The foreign genes will be expressed in the bacteria.
1. It must be able to replicate2. There must be some way to introduce vector DNA into the cell3. There must be some way of detecting its presence, preferably by plating techniquesMost common vectors are: Plasmid, phage λ and viruses
Discovered in an experiment where bacteriophage lost its plaque formation in E.coli Enzymes that recognize a specific base sequence in a DNA molecule It makes two cuts, one in each strand, generating 3’-OH and 5’-P termini Types of termini produced: Flush or blunt end Cohesive or sticky end
The number of cuts made in the DNA from specific organism is limited A particular restriction enzyme generates a unique family fragments from a DNA molecule