1. PCR and Gel Electrophoresis
The Polymerase Chain Reaction
Denaturation, Annealing, Elongation
Gel Electrophoresis
Application in forensic science

2. The Polymerase Chain Reaction
A process that is used to make a huge number of copies of a DNA sequence in a laboratory, quickly and without the need for a host organism
PCR is DNA replication of a specific region of the genome, outside of the nucleus of a cell
____________

3. TeachWithFergy Preview File
Please enjoy this preview of your Power Point.
Some slides appear blank because they have been removed.
Other slides may have on them, this represents writing that has been removed.
Please note that the Entire Unit Package can also be purchased at a steep discount from my Store.

4. Step 1 - Denaturation Cycle 1 ____________
This occurs when the DNA strand is heated to 94 to 96 °C for 20 to 40s, causing the hydrogen bonds holding the two strands together to break.

5. This slide has been removed

6. Step 3 - Elongation
Elongation: Heat to 72°C for DNA polymerase (Taq polymerase) to extend the primers using free-floating nucleotide precursors to make complementary copies of each template strand.
Taq polymerase is a special DNA polymerase found in the bacteria thermus aquaticus. __________
Note, ……………..

7. This slide has been removed

8. Cycle 3
Repeat the same steps again
____________
Once this repeats 20 times, most of the segments will be pure target DNA

10. This slide has been removed

11. Summary
____________
There is enough DNA in a hair follicle or a tiny blood spatter to perform PCR.
Once the DNA of interest has been amplified using PCR, it is analyzed using different methods

12. Gel Electrophoresis
Once the targeted DNA sequence has been amplified by PCR, it needs to be separated and purified from the rest of the contents in the test tube.
____________

13. This slide has been removed

14. Step 1

15. Step 2
A molecular marker is a DNA fragment of known size that is used to determine the lengths of unknown fragments by comparison (a standard)
____________

16. This slide has been removed

17. Step 4
To be able to see ……………

18. Why?
Using gel electrophoresis, researchers can compare the size of the DNA fragments from an unknown sample to the size of the DNA fragments from a known sample
____________
These conclusions may include:
……………..
the identity of the perpetrator of a crime
……………….

19. How?
___________
No two people will have the same number of bases in those areas
Example
Target Sequence
# of bases for Susan
# of bases for Jim A
100
115 B 56 77

20. This slide has been removed

21. Who is the daddy?

22. However, its looks more like this. Who is guilty???

23. Video has been removed. In the full version, you simply click on the video link and it opens for you.
NOVA Simulation