Making Recombinant DNA
Recombinant DNA
Definition
Recombinant DNA is DNA made by joining pieces from different sources. In cloning, this usually means combining a plasmid with a gene of interest.
How recombinant DNA is made
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1
Step 1: Cut the plasmid open with a restriction enzyme.
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2
Step 2: Cut out or prepare the gene of interest.
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3
Step 3: Mix the gene and plasmid so the ends can match.
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4
Step 4: Use DNA ligase to seal the DNA together.
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5
Step 5: Check that the plasmid now contains the gene.
Gene of interest
The gene of interest is the DNA piece the scientist wants to study or copy.
Why this matters
Once the gene is inside the plasmid, it can be carried into a host cell and copied many times.
Before and after ligation
Before
- Plasmid is cut open
- Gene is separate
After
- Gene is inserted into plasmid
- New recombinant DNA molecule forms
What is recombinant DNA?
Recombinant DNA combines genetic material from different sources.
Correct answer: DNA made by joining DNA from different sources
What is the purpose of DNA ligase in cloning?
Ligase seals the DNA backbone so the pieces become one molecule.
Correct answer: It joins the gene and plasmid together.
The gene of interest is usually inserted into a:
Plasmids are commonly used as cloning vectors.
Correct answer: Plasmid