DNA Fingerprinting

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DNA Fingerprinting

• Identifying individuals from their DNA

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StarterRearrange the pictures to show the
sequence ofDNA fingerprinting
Cleavage of DNA by restriction enzyme
DNA comparison
Cell sample
X ray film Used to detect radioactive DNA pattern
Separation of DNA fragments by electrolysis
Binding of radioactive DNA probe
Transfer to nylon Membrane (Southern Blot)
Membrane washed to remove excess probe
Extracted DNA
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Genetic fingerprinting process

• Extraction and digestion of DNA with restriction
  enzymes
• Separation of DNA fragments and southern blotting
• Hybridisation of DNA probes to nylon membrane
• Development of membrane with
• x-ray film

TASK In 4 groups you are going to represent the
key stages of the process in a series of diagrams
with detailed explanations
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(No Transcript)
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16.8 Genetic fingerprinting

• 10.1 Coordination.

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• Learning outcomes

• Success criteria

• By the end of this lesson I will know
• What genetic fingerprinting is
• How genetic fingerprinting is carried out and the
  results interpreted
• What genetic fingerprinting is used for

• By the end of this lesson I can
• Describe the theory behind genetic fingerprinting
• Produce a flow diagram of the key stages in the
  process
• Make a concept map to summarise the uses of
  genetic fingerprinting
• Answer exam questions about genetic
  fingerprinting

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Genetic fingerprinting - background
95 of the human genome consists of INTRONS
(non-coding DNA)
E1
E2
Intron
CORE SEQUENCE Repetitive DNA sequence within
intron

• Individuals have a unique pattern of core
  sequences in their DNA
• The number of different core sequences varies
  between individuals and...
• The length of each core sequence also varies

The more closely related two individuals are the
more similar their core sequences will be e.g.
Identical twins
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Genetic fingerprinting basics
Because everyones DNA is unique DNA
fingerprinting can be used for identification
1) Isolation DNA is extracted from blood, hair
or semen. Increase the quantity using PCR.
2) Fragmentation the DNA is cut into fragments
using restriction enzymes
3) Separation the DNA sections are separated
using electrophoresis
4) Comparison the DNA is compared to a sample
from the crime scene
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Genetic fingerprinting process

• Extraction and digestion of DNA with restriction
  enzymes
• Separation of DNA fragments and southern blotting
• Hybridisation of DNA probes to nylon membrane
• Development of membrane with
• x-ray film

TASK In 4 groups you are going to represent the
key stages of the process in a series of diagrams
with detailed explanations
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DNA Fingerprinting the process
Extraction
Digestion
Separation
Hybridisation
Development
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DNA Fingerprinting the process
Extraction
Digestion
Separation
Hybridisation
Development
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Summary questions

• Answer summary questions 1 and 2 from page 278 of
  the textbook
• Answers
• Very small amounts of DNA may be gathered from a
  crime scene so PCR is used to increase the
  quantity available for analysis
• (a) suspect B was present since genetic
  fingerprint matches that of the blood
• (b) The victims DNA fingerprint rules out the
  possibility of blood found having come from them

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Uses of genetic fingerprinting

• Make a concept map to summarise and explain these
  different uses of genetic fingerprinting

Paternity tests
Identify criminals
Testing genetic variability in a population
Genetic fingerprinting
Medical diagnosis of disease
Selective breeding of plants and animals
Identify microbes

• Refer to information on pages 277-279 of the
  textbook to help you

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Plenary / Homework

• Read through the application of genetic
  fingerprinting on pages 278-279 and answer the
  application questions

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• Learning outcomes

• Success criteria

• By the end of this lesson I will know
• What genetic fingerprinting is
• How genetic fingerprinting is carried out and the
  results interpreted
• What genetic fingerprinting is used for

• By the end of this lesson I can
• Describe the theory behind genetic fingerprinting
• Produce a flow diagram of the key stages in the
  process
• Make a concept map to summarise the uses of
  genetic fingerprinting
• Answer application style questions about genetic
  fingerprinting