How to Mess with DNA for Fun and Profit
OR
OR
How to Make a Mouse Glow in the Dark
What the heck is Recombinant DNA?
Recombinant DNA is what you get when you combine DNA from two different sources.
For example:
Mouse + Human DNA Human + Bacterial DNA Viral + Bacterial DNA Human + (other) Human DNA (It’s sort of like Frankenstein-DNA!)
Why Make Recombinant DNA?
Recombinant DNA Technology May Allow Us To:
• Cure or treat disease • Genetically modify our foods to increase
flavor, yield, nutritional value or shelf-life • Better understand human genetics • Clone cells or organs
Molecular Biology’s Best Friends: Bacteria
Why use bacteria?
• They’re relatively simple organisms. • They reproduce very quickly and asexually (this means that the “daughter” cells will contain the exact same DNA as the “parent” cell). • It’s pretty easy to get DNA back into the bacteria after you’ve changed it. • We can mess around with their DNA and kill a lot of them during our experiments and nobody gets mad. ;-)
Now for a little vocabulary…
Small, circular pieces of “extra” DNA found in bacteria.
Plasmids
Plasmids often carry antibiotic resistance.
Restriction Enzymes: Molecular Scissors
A restriction enzyme (RE) is a specialized protein that cuts DNA in a very specific place. • Different REs cut at different places along the nucleotide sequence.
Restriction Enzymes, continued
• Any piece of DNA cut with a certain restriction enzyme will “stick” to any other piece cut with that same RE, even if they come from different sources.
Restriction Enzymes, Cont.
What do you notice about these “restriction sites” (places where restriction enzymes cut)?
Cool, but what good are they? Let’s find out…
Insulin for Diabetics: The Old Way
Insulin for Diabetics: The New Way
Step 1: Isolate (find) the human gene responsible for producing insulin and decide where you want to put it.
In this case, we