pARA-R Restriction Digest: An Introduction to Plasmids and
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Transcript pARA-R Restriction Digest: An Introduction to Plasmids and
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pARA-R Restriction Digest:
An Introduction to Plasmids and Restriction Enzymes
Laboratory 2a
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Overview
Purpose:
Examine role of restriction endonucleses (enzymes) in genetic
engineering
Examine a bacterial plasmid and its use in biotechnology
Methods:
Preparing the pARA – R restriction digest
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Introduction
Restriction enzymes
Cut DNA molecules from various
organisms and recombine pieces
Recombinant DNA
Restrict the growth of viruses in
bacteria
Digest the DNA molecule at specific
nucleotide sequences
Restriction fragments
DNA fragments
Sticky ends
Allow annealing and
recombination of DNA fragments
from different sources
Engineering the Plasmid: ligation of rfp gene into p-ARA
Bruce Wallace
BamH I
sticky end
Hind III
sticky end
Hind III
sticky end
BamH I
sticky end
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Introduction
Bacterial plasmids
Circular pieces nonessential DNA
found in bacteria
Can be engineered to carry genes
Express proteins encoded by these
genes
pARA – R
Recombinant DNA plasmid
Engineered to express rfp gene
Produces a mutant Red
Fluorescent Protein (mFP)
Restriction digest of pARA-R
Recombinant plasmid of interest
pARA-R
4720 bp
rfp
702bp
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Recombinant Plasmid pARA - R
Important control elements:
araC
Protein to help bacteria make other
proteins
Encoded by genes inserted into
plasmid
pBAD
Site where RNA polymerase binds to
initiate transcription
rfp
Hind III & BamH I
Restriction enzymes
ampr
Antibiotic resistance gene
Encodes beta lactamase
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Materials
Reagents:
Equipment & Supplies
pARA-R (70 ng / μL)
P-20 micropipette and tips
Restriction enzymes
1.5 mL microfuge tubes
BamH I
Minicentrifuge
Hind III
37oC water bath
Markers
2.5x restriction buffer
Distilled water (dH2O)
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What will you need to do?
Aliquot:
pARA – R
Enzyme mix
2.5x restriction buffer
Turn on water bath the day before lab
37oC
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Methods
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1. Preparing the pARA-R
Restriction Digest
Three tubes:
pARA-R
Enzyme mix
2.5x restriction buffer
Tube
2.5x
buffer
dH2O
pARA - R
Enzyme
mix
Total
volume
A+
4 μL
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4 μL
2 μL
10 μL
A-
4 μL
2 μL
4 μL
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10 μL
Obtain 2 clean 1.5 mL microfuge tubes
Label as “A+” and “A-”
Use fresh tip and add 4 μL of 2.5x restriction
buffer to both tubes
Add 2 μL dH2O to “A-”
Fresh tip and add 4 μL of pARA – R to both
tubes
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1. Preparing the pARA-R
Restriction Digest
A+ tube
Teacher will dispense enzyme mix
2 μL
Cap tubes and gently “flick” to mix
Tube
2.5x
buffer
dH2O
pARA R
Enzyme
mix
Total
volume
A+
4 μL
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4 μL
2 μL
10 μL
A-
4 μL
2 μL
4 μL
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10 μL
Minifuge
Balance with other tubes
Place both tubes in 37oC water bath for 60 minutes
Either go directly to Lab 4a or freeze until ready to complete
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Conclusions
Will result in 2 restriction fragments
4018 bp with ampr gene and control regions
702 bp with rfp gene
Bruce Wallace
Restriction analysis of pARA-R
Restriction fragments after digest with Hind III and BamH I
BamH I
Hind III
4018 bp
BamH I
Hind III
702bp