Write down three key points for each: PCRElectrophoresis

Objectives State that gel electrophoresis is used in DNA profiling. Describe the application of DNA profiling to determine paternity and also in forensic investigations. Analyse DNA profiles to draw conclusions about paternity or forensic investigations. Outcomes 3: Outline the use of gel electrophoresis in DNA profiling. 5: Explain the applications of DNA profiling. 7: Consider the social, moral and ethical issues surrounding DNA profiling. Key terms: electrophoresis, DNA fingerprinting, paternity.

So how is DNA used in Forensics? DNA is used as a means of conviction via a technology known as DNA profiling. DNA profiling involves analysing the variation of DNA in the human population by looking at certain regions of our chromosomes.

DNA Profiling A DNA profile created by analysing the variation in specific regions on the human chromosomes. By calculating how many SHORT TANDEM REPEATS are contained in each specific region of interest.

STR (short tandem repeat) Analysis Example: Let’s say that on the two chromosome 13’s in your body (one from dad, one from mum). The short tandem repeat characteristic of region D13S317 is ATCGATCGATCG Then the amount of ATCGATCGATCG you have at that area at each chromosome 13 becomes highly diagnostic.

DNA profiling After a process known as Gel Electrophoresis is preformed the DNA short tandem repeats are shown as fluorescent bands in a gel.

Gel electrophoresis Lane 1 Lane Markers Sample from Crime Scene 1 Suspects The short tandem repeat characteristic of region D13S317 is ATCGATCGATCG The more copies of the repeats the bigger the fragment size Each sample has two bands, one from the maternal chromosome 13 and one from the paternal chromosome 13.

Where could DNA profiling be useful to us? Outcomes 3: Outline the use of gel electrophoresis in DNA profiling. 5: Explain the applications of DNA profiling. 7: Consider the social, moral and ethical issues surrounding DNA profiling. Key terms: electrophoresis, DNA fingerprinting, paternity.

Complete the sheets looking at analysing DNA profiles. Outcomes 3: Outline the use of gel electrophoresis in DNA profiling. 5: Explain the applications of DNA profiling. 7: Consider the social, moral and ethical issues surrounding DNA profiling. Key terms: electrophoresis, DNA fingerprinting, paternity.

Paradigm shift Before the advent of DNA profiling blood typing was used in paternity and forensic testing. What are the disadvantages of blood typing for this? Outcomes 3: Outline the use of gel electrophoresis in DNA profiling. 5: Explain the applications of DNA profiling. 7: Consider the social, moral and ethical issues surrounding DNA profiling. Key terms: electrophoresis, DNA fingerprinting, paternity. Blood typing can only exclude a person not confirm anything with reliability or certainty. What criteria are necessary in assessing the reliability of evidence to allow new theories and developments to allow those currently accepted and practiced?

What issues surround the use of DNA profiling technology? How has it helped society? Outcomes 3: Outline the use of gel electrophoresis in DNA profiling. 5: Explain the applications of DNA profiling. 7: Consider the social, moral and ethical issues surrounding DNA profiling. Key terms: electrophoresis, DNA fingerprinting, paternity.