Part 1- DNA Cloning/ Recombinant DNA/ Genetic Engineering

Procedures: Gene Cloning with Bacterial Plasmids; Nucleic Acid Hybridization; Genomic Library; Polymerase Chain Reaction (PCR)

Gene Cloning with Bacterial Plasmids

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Describe It

• Small circular double stranded DNA molecule

• DNA can be represented by different colors if radioactive (probe attached)

Analyze It

Parts: Two Cells, Plasmid, Gene of interest

1. Plasmid is isolated from bacterial cells and so is DNA from other organism
2. Both DNA samples are cut with a restriction enzyme
3. DNA piece is put into plasmid creating a recombinant DNA
4. Plasmid is put into bacteria cell
5. Host cell is grown in culture to form a clone of cells
6. Each clone is then used for its specific purpose

Apply It

• Gene cloning is a process that produces many copies of a gene of interest. These copies can be used in sequencing the gene, in producing its encoded protein, or in basic research.

1. Make insulin cells for someone who's body doesn't
2. Alter bacterial DNA to clean up oil spills
3. Genes can be used for pesticides
4. Dissolve blood clots

Synthesize It

• Gene cloning could allow the creation of new proteins which can alter the form of anything that they are placed into.
• This makes me think of Dolly the sheep. ALL of her cells were cloned and it makes me wonder what else could be?

Argue for or Against it

I am for genetic cloning of proteins. I believe that it is a great new technology that many people depend on when they have a missing protein. However, I am not in favor of cloning of people or animals. This, in my opinion, has many moral issues that get in the way.

Nucleic Acid Hybridization

Describe It

• dark spots (after probe has been attached and is under the film)

Analyze It

Parts: Multiwell plates, nylon membrane, solution, probe, DNA

1. Plate by Plate, cells from each well are transferred to a defined spot on a special nylon membrane.
2. The membrane is treated to break open the cells and denature their DNA.
3. The resulting single-stranded DNA molecules stick to the membrane.
4. The membrane is then incubated in a solution of radioactive probe molecules complementary to the gene of interest.
5. The single-stranded probe can then base-pair with any complementary DNA on the membrane.
6. Excess DNA is then rinsed off.
7. The membrane is laid under photographic film, allowing any radioactive areas to expose the film.
8. This location can be traced back to the original well containing the bacterial clone that holds the gene of interest.
   

Apply It

• Detects a specific DNA sequence within a mixture of DNA molecules.

1. Allows researchers to screen the collection of bacterial clones for different genes.
2. Nucleic Acid Hybridization allows for a quicker search through the many different clones.
   
   

Synthesize It

• This makes me think of my dog. When my dad takes her hunting it's her job to find or track the bird. This is similar to how the probe finds and tracks the DNA.
  
  

Argue for or Against it

I am for this because I believe that it is very helpful to scientists that work with many different genes and causes no harm.

Genomic Library

Describe It

• Bacteria, small circular DNA

Analyze It

Parts: DNA, cloning vector

1. Treat the DNA so it breaks into pieces
2. Organize the DNA by length
3. Insert into cloning vector

Apply It

• A genomic library is a collection of many bacterial or phage clones. Each clone carries copies of a particular DNA segment from a foreign genome, integrated into an appropriate DNA vector, such as a plasmid or a trimmed-down phage genome.

1. Allows scientists to see procedures that have already been done
2. Saves using resources

Synthesize It

• This makes me think of a library filled with many different types of books.

Argue for or Against it

I think that this is a good thing for scientists to have because it saves them a lot of work redoing things that have already been done as well as saving resources.

Polymerase Chain Reaction (PCR)

Describe It

• Double stranded DNA

Analyze It

Parts: Double Stranded DNA

1. Denaturation: Heat briefly to separate DNA strands
2. Annealing: Cool to allow primers to form hydrogen bonds with ends of target sequence
3. Extension: DNA polymerase adds nucleotides to the 3' end of each primer
4. More cycles can occur, each yielding more molecules

Apply It

• With PCR, any specific segment -- the target sequence -- within a DNA sample can be copied many times completely in vitro.
• This allows scientists to get more information from a smaller strand of DNA

Synthesize It

• This reminds me of the copy paste feature on a computer because you can select what you want copied and then 'paste' new copies.

Argue for or Against it

I am for this because it appears to be a simple and fast way to create more DNA molecules and causes no harm.