DNA Technology

I. What Can We Do With DNA?

Due to recent advancements in technology, we can now use DNA in many ways.

These are 3 common ways that scientists use DNA:1. Analyze DNA by gel electrophoresis (DNA

fingerprinting)2. Create genetically modified organisms (GMOs)

by transgenic manipulation3. Copy DNA using polymerase chain reaction (PCR)

II. What is gel electrophoresis?

• In the 1970s, the powerful tool of DNA gel electrophoresis was developed. This process uses electricity to separate DNA fragments by size as they migrate through a gel matrix.

II. What is gel electrophoresis?

• How it works:1. An agarose gel is made. This gel is porous like a

sponge.2. DNA is cut into fragments by restriction

enzymes3. The DNA fragments are pipetted into wells

(holes) at one end of the gel.4. The gel is placed in a buffer solution and an

electrical current passes through the solution.

II. What is gel electrophoresis?• How it works:5. Since DNA has a negative (-) charge, the DNA

starts moving to the positive (+) charge.6. The smallest DNA fragments move fastest, and

the largest DNA fragments move slowest through the gel.

7. A pattern of bands appears that can be used to determine paternity, solve crimes, or analyze organisms in other ways.

II. What is gel electrophoresis?

II. What is gel electrophoresis?

Molecular biologist

III. What are genetically modified organisms (GMOs)?

• Genetically modified organisms are plants and animals that have had their DNA altered (changed) in some way.

III. What are genetically modified organisms (GMOs)?

• How they do it:1. The desired gene is isolated and placed in a vector (like a

virus).2. The vector is allowed to infect the plant so that the

plant’s cells now have the desired gene.3. The plant’s cells are tested to determine which ones took

up the desired DNA. These cells are then placed in a medium so that they can grow into an adult plant.

OR, there is also a method that uses a “gene gun”. In this method, pellets of metal coated with DNA are fired at plant cells.

And in animals:

III. What are genetically modified organisms (GMOs)?

Do this simulation

III. What are genetically modified organisms (GMOs)?

Why modify organisms?• GMO plants and animals can be modified to grow faster,

more cheaply, and to make desired products. Examples:• Bt corn was engineered to produce its own pesticide. If

bugs eat it, they die.• “Golden rice” was engineered to produce vitamin A for

people in countries where the population is deficient in this vitamin.

• Bacteria have been engineered that can produce human insulin for people with diabetes.

III. What are genetically modified organisms (GMOs)?

IV. What is polymerase chain reaction?

• PCR is a method for amplifying DNA. When scientists want to analyze DNA, they need to make lots of copies of it. PCR allows scientists to make millions of copies in approximately 2 hours.

IV. What is polymerase chain reaction?How they do it:1. The DNA is heated to separate the DNA into

single strands (this is called denaturing the DNA).2. The DNA is cooled and primers anneal (stick to)

the DNA.3. Taq polymerase starts at the primers and

synthesizes a complimentary DNA strand.4. The process repeats over and over until enough

copies are made.simulation

And now for…

The PCR song