DNA Technology

What is DNA Technology?Its a set of methods

Name some of these methods:Cut DNA into segments

1

2

What cuts the DNA?Restriction enzymes

Another method?Gel electrophoresis

Why use it?To separate segments

Activity: Restriction enzymes

What is done with the segments?Transfer to another organism

What are they transferred into in E. coli?

A plasmid

(E. coli)

What are these ‘new’ plasmids called?

Recombinant DNA plasmids

3

4

Activity: Cloning a gene in bacteria

(also called a ‘vector’ )

What is done with these ‘new’ plasmids?

Put back into E. coli

E. Coli continues living

and dividing

But, what new capability does E. coli have?

Produces a ‘new’ protein

From that gene segment

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6

Used to study and manipulate genetic material

What are the methods used for?

Called?Genetic engineering

Or, recombinant DNA technology

The basic techniques of genetic engineering have many applications

DNA Technology and useful products

What was the world’s first genetically engineered pharmaceutical product?

Insulin

Before modern biotechnology, where did insulin come from?

Cows, pigs, horses

Why is the genetically engineered insulin better?

Its made from a human gene

Does not cause allergic reactions

    

gene A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses)

Ample supply available

What is the name of the technique used to make insulin?

Recombinant DNA technology

How does the recombinant DNA technique work?

DNA carrying a gene of interest is taken from a (e.g., a human) cell

The gene is inserted into the DNA of another (host) cell

The host cell now contains recombinant DNA

recombinant a molecule carrying DNA from more than one organism

The host cell multiplies

What happens to the DNA?The desired protein is produced

A quick look:

Humulin production

• Huge vats

• Liquid culture of bacteria

• Bacteria contain insulin gene

Insulin collected, purified, tested for quality, packaged

• And, insulin is produced

Where else is recombinant DNA used?

To introduce a gene into crop plants

The gene gives resistance to specific herbicides

What other crop plants can you think of?

e.g., rice, soybeans, cotton

Look at the golden rice activity

Have you heard about the Flavr Savr tomato?

Its been genetically engineered…

To reduce rate of spoilage

What does this mean?

… a marketing advantageIt can sit on the shelf longer

It can be picked at a later stage of ripeness

How is the stone washed denim look achieved?

Via genetic engineering…

• Recombinant DNA techniques are used

• To clone cellulase genes in bacteria

• To produce large quantities of cellulase

To sell to textile manufacturers

What does the enzyme do?

It partially breaks down the cotton fibers(They also wear out faster!)

Have you ever skied on artificial snow?

This is another example of recombinant (r) DNA technology…

What has r DNA technology done for skiing?

Increase expression of a bacterial protein

Called SnowMax

Used in snow making machines

Mix cold water and protein & huge amounts of snow are produced

Activity: Applications of DNA technology

Gel electrophoresisWhat would you do if you needed to analyze the DNA from a crime scene?

Collect DNA samples

• Extract DNA

1 2 3

From what? The crime scene itself (1)

And any suspects (2, 3)

Then what’s next?

• Cut &/or amplify the DNA samples

Activity: Gel electrophoresis of DNA

What are these fragments called?

Restriction fragments

• Load DNA into wells• Turn on power supply

• Watch fragments travel through gel

• Observe separated fragments

What do you know about DNA to cause the fragments to travel in the gel?

(PO4- ) Length

Compare the results

1 2 3

What is this field of science called?

1 2 3

Which DNA sample matches DNA from the crime scene?

Do you think this person is guilty of the crime?

Learning check

1. A recombinant DNA molecule _____.

a. is necessary for manufacturing protein on a large scale

b. is produced in yeasts

c. is the product of a defective gene

d. requires DNA from two different individuals-perhaps even individuals from different species

e. requires the use of cDNA

Learning check

1. A recombinant DNA molecule _____.

a. is necessary for manufacturing protein on a large scale

b. is produced in yeasts

c. is the product of a defective gene

d. requires DNA from two different individuals-perhaps even individuals from different species

e. requires the use of cDNA

This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene.

Which of these DNA fragments is common to both the victim and Suspect 1?

2.

A B C D E

Activity: DNA Fingerprinting

This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene.

Which of these DNA fragments is common to both the victim and Suspect 1?

2.

A B C D E

This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene.

Which of these DNA fragments is common to both the victim and Suspect 2?

3.

A B C D E

This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene.

Which of these DNA fragments is common to both the victim and Suspect 2?

3.

A B C D E

4. Why is Suspect 1 considered more likely to have committed the crime than Suspect 2?

a The crime scene sample contains DNA fragments from both the victim and Suspect 1.

b The crime scene sample contains DNA fragments from both the victim and Suspect 2.

c Suspect 1 and the victim have more DNA fragments in common that do the victim and Suspect 2.

d Suspect 2 and the victim have more DNA fragments in common that do the victim and Suspect 1.

e Suspect 1 and Suspect 2 have more DNA fragments in common than either have in common with the victim.

4. Why is Suspect 1 considered more likely to have committed the crime than Suspect 2?

a The crime scene sample contains DNA fragments from both the victim and Suspect 1.

b The crime scene sample contains DNA fragments from both the victim and Suspect 2.

c Suspect 1 and the victim have more DNA fragments in common that do the victim and Suspect 2.

d Suspect 2 and the victim have more DNA fragments in common that do the victim and Suspect 1.

e Suspect 1 and Suspect 2 have more DNA fragments in common than either have in common with the victim.

5. In gel electrophoresis, DNA molecules migrate from _____ to _____ ends of the gel.

a acidic ... basic

b negative ... positive

c basic ... acidic

d long ... short

e positive ... negative

5. In gel electrophoresis, DNA molecules migrate from _____ to _____ ends of the gel.

a acidic ... basic

b negative ... positive

c basic ... acidic

d long ... short

e positive ... negative

For Thursday

Continue reading chapter 12

More detail on topics covered in Ch 12

Remember! Exam #2, Tuesday, 11/6

The exam will cover:

Chapter 6, Cell Respiration

Chapter 7, Photosynthesis

Chapter 12, DNA Technology

For next Tuesday