2. • Clones
– Genetically identical molecules, cells, or organisms
all derived from a single ancestor
• Cloning
– The production of identical copies of molecules,
cells, or organisms from a single ancestor
3. Why cloning -
• DNA clones are used to find genes, map them,
and transfer them between species
• Cloning technology is used to find carriers of
genetic disorders, perform gene therapy, and
create disease-resistant plants
14. Selection
• Blue White Screening -
–Only plasmids with functional lacZ gene can
grow on Xgal
lacZ functional => polylinker intact =>
nothing inserted, no clone
lacZ(-) => white colonies polylinker
disrupted => successful insertion &
recombination!
15. A Revolution in Cloning :
Polymerase Chain Reaction
Requirement
1. Target DNA
2. Two Primers
3. Four dNTPs
4. DNA Polymerase
16. Natural habitat of Thermus aquaticus
• Thermostable DNA Polymerase is used like-
Taq DNA Polymerase from Thermus aquaticus
Pfu DNA Polymerase from Pyrococcus furiosus
18. Application of Cloning
• Development of methods for cloning higher
plants and animals represents a significant
advance in genetic technology
– Improving crops
– Producing domestic animals
19. • Cloned plants and animals are used in
research, agriculture, and medicine
• Single base changes then detected by one or
more of following:
-dot blot technique
-Restriction enzyme analysis (RFLP).
-direct sequencing of DNA.
• PCR to detect HIV
20. • Crucial forensic evidence may be present in
very small quantities often too little material
for direct DNA analysis.
• PCR also possible on extensively degraded
DNA examples include DNA from single dried
blood spot, saliva (on cigarette butt), semen,
tissue from under fingernails, hair roots.
