CreateFingerprint

Student Handout: Create A DNA Fingerprint

Name: Kevin Lee

From the video:

1. What evidence might kidnapped children leave behind that would contain their DNA?
Food, Drinks, Cigarrets, lolipops, anything they touched.

2. How easily do you think DNA evidence can be contaminated?

Dna evidence can be contaminated when DNA from an outside source gets mixed up with the DNA tested

3. How does a forensic department avoid confusing DNA profiles in a contaminated sample?

They profile the lab workers so if DNa does get contaminated, they don’t get confused by the lab workers DNA profile

Activity:

Goal
Since 1984 forensic scientists have been using DNA profiling to identify the potential perpetrators of crimes and to locate missing persons. In this Web-based activity, you will:
Use the Internet to show how a DNA fingerprint is created.
Identify the steps of the process for creating a DNA fingerprint.
Solve a mystery using a DNA fingerprint.

Procedure

1. Carefully enter the following URL into the address bar of the Internet browser on your computer: http://www.pbs.org/wgbh/nova/sheppard/analyze.html

You should be on the NOVA Online page entitled “Create a DNA Fingerprint.”

2. Read through the introductory page.

3. Click on Part 1: It Takes a Lickin’. Your job is to determine which of Jimmy Sweet’s sisters licked the holographic image off his NOVA hologram lollipop.

4. Click on Part 2: DNA Fingerprinting at the NOVA Lab. This will take you to a screen with a virtual lab and directions for creating a DNA Fingerprint.

(NOTE: You will need Shockwave to run the virtual lab. If you do not have Shockwave, there should be a link in place of the virtual lab that will direct you to the Shockwave download page. After you download the free software, the virtual lab should appear.)

Follow the steps very carefully to create a DNA Fingerprint.

Each step in this process will be explained so take the time to read these explanations carefully.
Each object in the directions is represented in the virtual lab.
Follow the steps by clicking on and dragging the related object until the object does the action in the step (e.g., the restriction enzymes container turns to pour into the DNA).
After each step you will need to click OK in order to go on to the next step.
Note that in order to pour anything into the “tray,” you will need to drag the item onto or slightly below the bottom of the tray until it changes to show the action of that step.
If you hurry and make a mistake, you will be sent back to the beginning of the activity to start all over again.
STOP when you get to “CHOOSE THE CULPRIT.”

5. What is the source of DNA used to create the fingerprint? Saliva

6. What is the function of the following materials or equipment used to prepare a DNA fingerprint?

Material
Function
restriction enzymes

They work like scissors, cutting the long DNA molecules at
Different sections

agarose gel

Acts as a molecular strainer allowing small amount of DNA to
Go through it. Sort of like Jell-o

electrophoresis

It moves molecules with a electrical current, and since DNA
Is slightly negative, it moves towards the positive end

nylon membrane

The DNA is transferred to the nylon membrane because it is
Hard to extract it directly form the eletrophoresis

probes

These are pieces of DNA that have been radioactively been
Labeled. They attach to certain parts of the DNA

x-ray film

It is used to locate the radioactive probes that attached parts
Of the DNA

developer

You put the film in the developer and shows the locations of
The DNA.

7. Click on Part 3: Choose the Culprit or continue by clicking on Choose the Culprit from the last screen of Part 2. Click and drag the DNA Fingerprint onto the suspects’ DNA fingerprint to find the culprit.

Which sister committed the crime? Honey

How did you determine this?­­­­­­­­­­­­­­­

Her DNA fingerprint matches up to the DNA fingerprint at the crime scene