DNA Fingerprinting Lesson plan gel

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					Lesson plan #2
A.J. Pettway/Debbie Bell
7th Grade Life Science

                                             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

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:


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.


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 add 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. Explain 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
            As a result of activities in grades 5-8, all students should develop:

                  o     Abilities necessary to do scientific inquiry

                  o     Understandings about scientific inquiry
           Life Sciences
           As a result of their activities in grades 5-8, all students should develop understanding of:

                 o     Reproduction and heredity

                 o     Diversity and adaptations of organisms

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

                 o     Abilities of technological design

                 o     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)

     I. References:

Web page to find national science teaching standards: http://www.nap.edu/readingroom/books/nses/html/

Web page to find supplies to teach biology: https://www3.carolina.com/onlinecatalog/

Web page with a list of individuals cleared by DNA evidence: http://www.pbs.org/wgbh/nova/sheppard/cleared.html
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.

                                                               Length of
Name of                       Date of           Date of      Incarceration
Defendant           Location Conviction         Release         (years)

Kenneth Adams          IL         Oct-78         Jul-96            19
Gilbert Alejandro      TX         Oct-90         Jul-94            14
Kirk Bloodsworth       MD         Mar-85         Jun-93             8
Mark Diaz Bravo        CA         Oct-90         Jan-94             4
Dale Brison            PA         Jun-91         Jan-94             4
Ronnie Bullock         IL         May-84         Oct-94            10
Kevin Byrd             TX         Aug-85         Oct-97            12
Leonard Callace        NY         Mar-87         Oct-92             6
Terry Chalmers         NY         Jun-87         Apr-95            7.5
Marion Coakley         NY         Aug-85         Sep-87             4
Ronald Cotton          NC         Jan-85         Jun-95            11
Rolando Cruz           IL         Jan-85         Nov-95            11
Charles Dabbs          NY         Apr-84         Aug-91             9
Dewey Davis            WV         Jan-87         Jun-94            7.5
Gerald Davis           WV         Jul-86         Jul-94             8
Frederick Daye         CA         Aug-84         Sep-94            10
Gary Dotson            IL         Jul-79         Aug-89             8
Timothy Durham         OK         Mar-93         Jan-97             5
Dennis Fritz           OK         Apr-88         Apr-99            12
Anthony Gray           MD         Oct-91         Feb-99             7
Edward Green           DC         Jul-89         Mar-90           0.75
Kevin Green            CA         Oct-80         Jun-96            16
Ricky Hammond          CT         Mar-90         Oct-92            2.5
William Harris         WV         Oct-87         Oct-95             8
Alejandro              IL         Jan-85         Nov-95            11
Anthony Hicks          WI         Dec-91         Jul-96             5
Larry Holdren          WV         Mar-84         Jun-99            15
Edward Honaker         VA         Feb-85         Oct-94            10
Vincent Jenkins        NY         Nov-83         not yet           U
Verneal Jimerson       IL         Dec-85         Jun-96            11
Jones Joe              KS         Feb-86         Jul-92             7
Calvin Johnson         GA         Nov-83         Jun-99            16
Richard Johnson        IL         Jan-92         Dec-95             4
Ronald Jones           IL         Jul-89         May-99            10
Kerry Kotler           NY         Mar-82         Dec-92            11
Steven Linscott        IL         Jun-82         Jan-85             3
Dale Mahan             AL         Jun-84         Dec-97            14
Ronnie Mahan           AL         Jun-84         Dec-97            14
Robert Miller          OK         Jan-88         Jan-98             9
Marvin Mitchell        MA         Jan-90         Apr-97             8
Perry Mitchell         SC         Jan-84         Aug-98            14
Vincent Moto           PA         Jan-88         Nov-95             9
Bruce Nelson       PA   Apr-85   May-91     9
Victor Ortiz       NY   Jan-84   Oct-96    14
Brian Piszczek    OH    Jun-91   Sep-94     4
Willie Rainge      IL   Oct-78   Jul-96    18
Donald Reynolds    IL   Feb-88   Nov-97     9
Fredric Saecker    WI   Jan-90   May-96     6
Ben Salazar        TX   Jan-92   Oct-97     5
Dwayne Scruggs     IN   May-86   Dec-93     8
David Shepard      NJ   Sep-84   Apr-95    11
Walter Smith      OH    Dec-86   Dec-96    10
Walter Snyder      VA   Jun-86   Apr-93     7
Steven Toney      MO    Apr-83   Jul-96    14
David Vasquez      VA   Feb-85   Jan-89     5
Billy Wardell      IL   Feb-88   Nov-97     9
Thomas Webb       OK    Jan-83   May-96    14
Troy Webb          VA   Apr-89   Oct-96     7
Dennis Williams    IL   Oct-78   Jul-96    18
Ron Williamson    OK    Apr-88   Apr-99    12
John Willis        IL   Sep-90   Feb-99     9
Glen Woodall      WV    Jun-87   May-92     4
Herman Kaglick    CAN   Jan-92   Jan-98     5
David Milgaard    CAN   Jan-70   Apr-92    23
Gordon Folland    CAN   Mar-95   Nov-96     3
Guy Paul Morin    CAN   Jul-92   Jan-95     2
Gregory Parsons   CAN   Feb-94   Feb-98   0.25

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