Notes 7DNA Fingerprinting

Key Questions

1. How is DNA evidence used to solve crimes?

2. How do scientists create DNA fingerprints?

3. Once created how do you read and compare DNA fingerprints?

DNA - Deoxyribonucleic acid

DNA is the hereditary material found in all cells.Its is a polymer made up of billions of nucleotides. The combination of nucleotides makes different proteins.

The Human Genome

Humans have 46 chromosomes which contain roughly 25,000 genes;1% of the genome.

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The location of a gene on a chromosome is called a

locus. Alleles are different forms

of the same gene.

Chromosome structure

Coding Regions & Non-coding regions

Portions of the DNA that code

for proteins

Portions of the DNA that doesn’t code for proteins

STR & VNTR length polymorphismsHemoglobin, Skin Pigment

The genome differs from person to person by .1%

DNA fingerprinting compares these non coding regions to determine if crime scene DNA matches suspect DNA.

Steps for creating a fingerprint

1. Isolate/Clean/Amplify the DNA sample(s).

2. Cut up the DNA with restriction enzymes.

3. Put DNA fragments through Electrophesis.

4. Take a picture.

5. Compare.

DNA Basics

DNA fingerprinting for paternity testing

Paternity Evidence

Paternity Evidence

CIS DNA Fingerprinting

CIS DNA Fingerprinting