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DNA finger printing lesson plan

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					Forensic Files: A DNA Dilemma I. Anticipatory Set
At the beginning of the class period, students will find case files on their desks that they are to read. The instructor will then explain that the file is from the LAPD and that the investigators there need the students’ help to solve a murder case.

II. Background
Students must have a firm grasp of DNA and heredity Basic knowledge of enzymes and what they do is a plus. Graphing Skills Students will benefit by having an understanding of the uniqueness of an individual’s DNA sequence

III. Abstract
The purpose of this lab activity is to demonstrate (through simulation) how DNA fingerprinting (or DNA profiling) might be used to solve a crime. In this activity, students perform restriction digests on DNA samples from four individuals, and then search for similarities between the individuals by running the restriction fragments on an electrophoresis gel. Because not two people ( except identical twins) have exactly the same DNA, a person's DNA fingerprint is unique and can be used for purposes of identification. This activity does not do a true DNA fingerprint. It simulates two of the three steps of DNA fingerprinting: restriction of DNA sample and separation by electrophoresis.

IV. Lesson Plan A. Goal:
The lesson is designed to expose students to a relatively new DNA technology and how it is used in a practical setting to identify individuals through DNA fingerprinting.

B. Content Objectives:
Through this activity students will learn: some properties of DNA, how Restriction Digestion uses enzymes to cut DNA, the process of separating DNA based on its size (gel electrophoresis), basic measurement technique, how to generate and use a standard curve, and the scientific method of investigation.

C. Materials: 
           4 ul. EcoRI enzyme 2 ul. BamHI enzyme 2 ul. HindIII enzyme 12 ul. lambda DNA (0.5 mg/ml) 20 ul. 2x multicore® restriction buffer 2 ul. loading dye 1Kb DNA ladder 1% agarose gel(1g. agarose/ 100 ml. TBE or TAE buffer —microwave and pour) 1 liter 1X TBE or TAE Buffer Carolina Blue® stain (or ethidium bromide and UV source) 5 microcentrifuge tubes 0.5 - 10 ul. micropipettors and tips

     

37oC water bath 1 set electrophoresis equipment 1 microtube rack 10 mm rulers 10 sheets of graph paper hot plate with magnetic stirrer or microwave oven

*please note that the above materials and a good portion of the lab can be cut out if one would rather supply students with a printout of a gel that has already been run.

D. Estimated Time:
The time required for the lesson is 2-3 50 minute class periods if doing the actual gel electrophoresis. Without running the gel it could be completed in a single 50 minute class period.

E. Procedure:
Teacher Preparation: KEEP IN MIND THAT THE DNA SAMPLES IN THIS LAB ARE ACTUALLY DIFFERENT RESTRICTION ENZYMES AND THE RESTRICTION ENZYME IS ACTUALLY LAMBDA DNA!! Before class the teacher should prepare the DNA gel as well as aliquot the three different enzymes (labeled as DNA for the demonstration), the DNA (labeled as enzyme), and the buffer solution. A 37°C water bath should be prepared in a beaker. Demonstration: After the students have read the case file the teacher should now gather the students around the demonstration table. To save time, tell the students that you are going to add an enzyme to the suspects’ DNA that will cut the DNA so that they will be able to tell them apart. Add 4ul EcoRI (labeled suspect 1 DNA) to 4ul lambda DNA (labeled Restriction Enzyme) in a 1.5ml reaction tube and to that ad d 8ul 2X buffer. Do the same with the remaining two enzymes but only use 2ul of each enzyme and 2ul DNA with 4ul 2X buffer. Incubate the 3 tubes for 45min in the water bath. After incubation, add 1ul loading dye to each of the tubes. Next, pipette 10-15ul of each sample into the wells of the gel. In the first or last lane on the gel, pipette 8ul of the 1Kb DNA ladder. Run electrophoresis at ~100v for about 30-45 minutes. During the time that the gel is running is a good time to teach the students how to generate the first standard curve using the ladder that is shown on the gel photo of the crime scene DNA. Also, go over how restriction enzymes act to cut DNA at specific sites allowing for differentiation of DNA strands from different individuals. E xplain how electrophoresis works because DNA is negatively charged and will go toward the positive electrode and that DNA strands of different sizes travel different distances. Smaller strands will travel shorter distances than larger fragments. After the gel has run and been stained. Make a copy of it for each group so that each group can generate their own standard curve to determine the size of the DNA fragments and compare that with the size they found the crime scene DNA to be. If using Caroline Blue® stain to stain the DNA bands, read the instructions that come with the kit.

F. Closure:
A great closure for this lesson is to display, read, or hand out a list of all of the people that have been exonerated and let out of prison based on this procedure of DNA fingerprinting. Following this lesson plan is an up-to-date list including the names and lengths of sentences served for crimes they did not commit.

G. Standards: Science as Inquiry
CONTENT STANDARD A:
As a result of activities in grades 5-8, all students should develop:

o o

Abilities necessary to do scientific inquiry Understandings about scientific inquiry

Life Sciences
CONTENT STANDARD C:
As a result of their activities in grades 5-8, all students should develop understanding of:

o o

Reproduction and heredity Diversity and adaptations of organisms

Science and Technology
CONTENT STANDARD E:
As a result of activities in grades 5-8, all students should develop:

o o

Abilities of technological design Understandings about science and technology

H. Assessment:
Take up student’s reports and graphs and grade them on completion, content, writing skills, and neatness Throughout the class period, walk around and assess participation Give handout of similar “who done it” activities (possibly a good place to work in paternity tests)

Cleared by DNA
The sheer number of inmates who have gained their freedom since the advent of forensic DNA testing in the late 1980s may surprise you. Below is an up-to-date list of those freed inmates, most of who were incarcerated for murder or rape. The list is maintained by the Innocence Project at the Benjamin N. Cardozo School of Law in New York City.

Name of Defendant

Date of Location Conviction

Date of Release

Length of Incarceration (years)

Kenneth Adams Gilbert Alejandro Kirk Bloodsworth Mark Diaz Bravo Dale Brison Ronnie Bullock Kevin Byrd Leonard Callace Terry Chalmers Marion Coakley Ronald Cotton Rolando Cruz Charles Dabbs Dewey Davis Gerald Davis Frederick Daye Gary Dotson Timothy Durham Dennis Fritz Anthony Gray Edward Green Kevin Green Ricky Hammond William Harris Alejandro Hernandez Anthony Hicks Larry Holdren Edward Honaker Vincent Jenkins Verneal Jimerson Jones Joe Calvin Johnson Richard Johnson Ronald Jones Kerry Kotler Steven Linscott Dale Mahan Ronnie Mahan Robert Miller Marvin Mitchell Perry Mitchell Vincent Moto Bruce Nelson Victor Ortiz Brian Piszczek Willie Rainge Donald Reynolds Fredric Saecker Ben Salazar Dwayne Scruggs David Shepard Walter Smith Walter Snyder Steven Toney

IL TX MD CA PA IL TX NY NY NY NC IL NY WV WV CA IL OK OK MD DC CA CT WV IL WI WV VA NY IL KS GA IL IL NY IL AL AL OK MA SC PA PA NY OH IL IL WI TX IN NJ OH VA MO

Oct-78 Oct-90 Mar-85 Oct-90 Jun-91 May-84 Aug-85 Mar-87 Jun-87 Aug-85 Jan-85 Jan-85 Apr-84 Jan-87 Jul-86 Aug-84 Jul-79 Mar-93 Apr-88 Oct-91 Jul-89 Oct-80 Mar-90 Oct-87 Jan-85 Dec-91 Mar-84 Feb-85 Nov-83 Dec-85 Feb-86 Nov-83 Jan-92 Jul-89 Mar-82 Jun-82 Jun-84 Jun-84 Jan-88 Jan-90 Jan-84 Jan-88 Apr-85 Jan-84 Jun-91 Oct-78 Feb-88 Jan-90 Jan-92 May-86 Sep-84 Dec-86 Jun-86 Apr-83

Jul-96 Jul-94 Jun-93 Jan-94 Jan-94 Oct-94 Oct-97 Oct-92 Apr-95 Sep-87 Jun-95 Nov-95 Aug-91 Jun-94 Jul-94 Sep-94 Aug-89 Jan-97 Apr-99 Feb-99 Mar-90 Jun-96 Oct-92 Oct-95 Nov-95 Jul-96 Jun-99 Oct-94 not yet Jun-96 Jul-92 Jun-99 Dec-95 May-99 Dec-92 Jan-85 Dec-97 Dec-97 Jan-98 Apr-97 Aug-98 Nov-95 May-91 Oct-96 Sep-94 Jul-96 Nov-97 May-96 Oct-97 Dec-93 Apr-95 Dec-96 Apr-93 Jul-96

19 14 8 4 4 10 12 6 7.5 4 11 11 9 7.5 8 10 8 5 12 7 0.75 16 2.5 8 11 5 15 10 U 11 7 16 4 10 11 3 14 14 9 8 14 9 9 14 4 18 9 6 5 8 11 10 7 14

David Vasquez Billy Wardell Thomas Webb Troy Webb Dennis Williams Ron Williamson John Willis Glen Woodall Herman Kaglick David Milgaard Gordon Folland Guy Paul Morin Gregory Parsons

VA IL OK VA IL OK IL WV CAN CAN CAN CAN CAN

Feb-85 Feb-88 Jan-83 Apr-89 Oct-78 Apr-88 Sep-90 Jun-87 Jan-92 Jan-70 Mar-95 Jul-92 Feb-94

Jan-89 Nov-97 May-96 Oct-96 Jul-96 Apr-99 Feb-99 May-92 Jan-98 Apr-92 Nov-96 Jan-95 Feb-98

5 9 14 7 18 12 9 4 5 23 3 2 0.25


				
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