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The Analysis of Pre-Digested Lambda ( ) DNA and Determining the lengths of each fragment Produced Using Gel Electrophoresis. Lab #8 (Chapter 20). Materials for Lab. Materials List @ each Station : (5) Vials w/ appropriate contents (see quick guide)
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The Analysis ofPre-Digested Lambda () DNA and Determining the lengths of each fragment Produced Using Gel Electrophoresis Lab #8 (Chapter 20)
Materials for Lab • Materials List @ each Station: • (5) Vials w/ appropriate contents (see quick guide) • 500 ml Beaker: used for TAE Buffer (need 300ml) • Case of pipette tips---be careful with!!!! • Electrophoresis Chamber • Pre-casted Gel with six wells prepared • Micropipette (to transfer 10 L) • 100 ml Grad. Cylinder • One Staining tray • Tape & sharpie pen • Other Supplies Needed located at other places: • 1x TAE Buffer Solution ------------------------------- on the cart • 1x Fast Blast Stain (need 120 ml)------------------- on the cart • Power Supplies: 1 in the back & another in the front of room
Basic Procedure I • Look over your supplies and lay them out • Locate the pipette tips and micropipette and practice moving 10 µL form blue “LD” tube to the clear tube (in beaker) • Obtain 300ml of TAE Buffer solution from the back of room (use your Beaker) & pour into the chamber. • Look at the Quick guide and ID the contents in the colored tubes. • Skip to step 3 & 4. Remove a gel cast from the sealed baggie. Remove the tape from both ends carefully. • Make a small corner cut on one end at the top of the gel near the six wells. Leave the gel on the tray. • Place the gel & tray into the chamber. Be sure that the wells are near the black (-) electrode. • Pour the 1x buffer solution into the chamber. Do not pour directly on to the gel. • Gently push down on the tray to submerge the entire gel and tray. The little holes will allow any air under the tray to escape allowing it to sink.
Loading the Gels w/Micropipette • Be sure that your Micropipette is set at “10.0” • Load your DNA samples into the correct well as follows from left to right using a micropipette. Closet to the corner cut of the gel. • Well #1: Lambda DNA (uncut) (yellow tube) • Well #2: Lambda cut w/PstI (violet or pink) • Well #3: Lambda cut w/EcoRI (green tube) • Well #4: Lambda cut w/Hind III (orange tube) I will take two groups at a time in the back or front of the room. While you wait answer all questions from your guide sheet. Pgs. 21-28
Basic Procedure III • Once all wells are loaded, I will cover the chamber with the lid • Attach your electrodes to the power source. Black = Negative Red = Positive Current can be: 100 V for 30 min. ideally
Staining your Gels For Overnight Staining: -Pour 150 ml of Staining solution (1X Fast Blast) into the tray. Let gels stand overnight. Pour off fluid next day. Record your results. **To record you results bring either a camera or you may use you cell phone to take capture an image of your gel results tomorrow.
Adding each digest to the correct well • Well #1 (Lane) = uncut Lambda DNA “L” • Well #2: Lambda DNA cut w/ PstI “P” • Well #3: Lambda DNA cut w/ Eco RI “E” • Well #4: Lambda DNA cut w/ HindIII “H”
After Gel is done Running • We will do Option 2 for visualizing our DNA “Overnight staining” • Fill your staining tray w/ 120ml of Fast Blast stain • Let stand overnight-cover w/saran wrap • Next day: pour off water • Record your results: Draw, pictures, etc. • Let dry and sit on your casting tray
Introductory Questions #6 Using your Lab Guide and textbook answer the following questions: Where do we obtain Restriction enzymes (endonucleases) and how are they named? What name do we use to describe two sequences of DNA that read the same in both directions? (lab pg. 22) Why are these sequences important? If a restriction enzyme made 9 cuts on the DNA then how many fragments would there be? To separate fragments of DNA Gel Electrophoresis is used. What voltage did we use and for how long? Which side (+/-) of the gel was the DNA loaded? How many base pairs does lambda DNA have? (see pg. 29)
Restriction Enzymes (Endonucleases) • Found in Bacteria & named as such: Restriction enzymeName of Bacteria • EcoRI Escherichia coli • Hind III Haemophilus influenza • Pst I Providencia stuartii • Bam I Bacillus amyloliquefaciens • Recognizes Palindromic Sequences • Cuts the all DNA and produces pieces (fragments) called RFLP’s. (Pg. 394) • RFLP: Restriction Fragment length Polymorphisms • RFLP’s can measure genetic relationships and generate a DNA fingerprint when separated on an agarose gel.
Restriction Fragment Analysis • Restriction fragment length polymorphisms (RFLPs) • Southern blotting: process that reveals sequences and the RFLPs in a DNA sequence • DNA Fingerprinting (DNA Profiling)
Gel Electrophoresis Pgs 392-394 • separates nucleic acids or proteins on the basis of size and electrical charge creating DNA bands of the same length • DNA has a net negative charge (use a positive charge in the gel)
Homework • Work on Lab 8: Complete all pages to Pg. 29 • Do IQ #5
Gel Electrophoresis • DNA fragments placed into “wells” in gel agarose • Electricity pulls on DNA fragments • Fragments travel at different rates based on size and ability to squeeze through swiss-cheese-like agarose
Intro. Q’s #7 for Chapter 20: Genetic Engineering • What does the acronym PCR stand for and what does this process do? • What does Gel electrophoresis allow us to do? • Give two applications of DNA profiling. • What are the advantages and disadvantages of genetic screening? • How is a cDNA library different from a genomic library? (p. 388-390) • Name two “vectors” that can be used for gene transfer. • Give two examples of a genetically modified crop or animal. • Briefly explain the process of gene therapy and give an example how it works. • Explain what a clone is and how it could be formed. • What are some of the ethical concerns about cloning? Give your opinion if you think cloning is something we shouldbe doing.
Lamda DNA-used in this lab • DNA comes from a Bacteriophage • Genome composed of 48,502 base pairs • Known: -(7) restriction sites for Hind III -Sizes for all eight Fragments
Restriction Enzymes used in the Lab Name of EnzymeSequence Recognized “Palindrome” -EcoRI G ….A A T T C C T T A A…. G -PstI C T G C A G G A C G T C -HindIII A A G C T T T T C G A A
Analyzing Your Data Determine the approximate size of your fragments using the known Hind III digest patterns as a standard (marker). • Visual estimation • Create a standard curve • Measure the distance (mm) each band traveled from the well. Be sure to measure from the bottom of the well to the bottom the band. • Record your measurements in the table • Estimate (visually) the number of base pairs the fragments would have by comparing with the actual number of base pairs for Hind III Fragments
Constructing a Standard Curve • Graph the following on Semi-log paper • (y-axis): Size of known fragments (Base pairs) • (x-axis): Distance each band moved (mm) ****Note: HindIII is used • Use a ruler and for each band measured, line up the distance it traveled with the standard line drawn. Look horizontally on the y-axis and determine the the number of Base pairs those fragments should be.
2nd Table will be needed for your data or the data from the image on ppt slide
Print out & Paste on pg. 34 of your lab if your bands are not visible
Measure (mm) DNA DNA DNA DNA Uncut w/PstI w/EcoRI HindIII Visible Fragments Fragment #1 Fragment #2 Fragment #3
Semi-Log Graphing Paper Pg. 40Graph your data or data from ppt slide
Key Points to Remember • The same DNA was used with all three enzymes • We know the Fragment sizes using HindIII (p.29) • Seven cuts & Eight Fragments • Will compare the fragments generated from PstI & EcoRI to that of Hind III in order to estimate how long the fragments fragments are. • This comparison will be observed through the separation of these fragments on Gel agarose. • Four wells will be used to compare
Biogenetic Engineering & Manipulating Genes Chapter 20
Lab #2-Results Crime Scene Suspect #1 Suspect #2 Hind III Extra band Similar pattern
Hind III EcoR I Measure the following Bottom of well Bottom of each band (mm)
Intro. Q’s #7 for Chapter 20: Genetic Engineering • What does the acronym PCR stand for and what does this process do? • What does Gel electrophoresis allow us to do? • Give two applications of DNA profiling. • What are the advantages and disadvantages of genetic screening? • How is a cDNA library different from a genomic library? (p. 388-390) • Name two “vectors” that can be used for gene transfer. • Give two examples of a genetically modified crop or animal. • Briefly explain the process of gene therapy and give an example how it works. • Explain what a clone is and how it could be formed. • What are some of the ethical concerns about cloning? Give your opinion if you think cloning is something we shouldbe doing.