Name
Period
Date
Contagion Lab
Introduction:
Contagious diseases are caused by “germs” (bacteria, viruses, or fungi) which are passed from one organism to
another. Contagious diseases can be “caught.” Different contagious diseases can be caught in different ways.
A sexually transmitted disease (STD) is any of a number of contagious diseases which are not caught through
casual contact - that is the normal contact with classmates, coworkers, and neighbors. STDs are transmitted
through intimate, sexual contact. Some STDs can be cured with antibiotics, others cannot be cured.
Human Immunodeficiency Virus (HIV) is an STD which can be caught when body fluids such as blood,
semen, or vaginal fluid enter the body. HIV is the virus which causes AIDS (Acquired Immune Deficiency
Syndrome), a lethal disease. HIV/AIDS cannot be cured. People in the early stages of the infection look normal
and healthy, but they can still spread the disease.
In this lab you will simulate how a contagious disease can spread through a population.
Materials:
Each student needs a test tube of fluid, a dropper pipette, a label mat, a strip of waxed paper, and a pair of goggles.
Method:
Put on your goggles. Place waxed paper on top of the label mat.
Fold the waxed paper over the edge of the mat to prevent slipping.
0
1
2
3
ROUND 0
1. Prepare a sample for pre-testing. Use your pipette to place 1 drop on the pretest spot.
To simulate contact find a partner and dump the contents of both tubes together.
Then divide the contents evenly between your tubes.
ROUND 1
2. Find a partner. Record their name on your data sheet and simulate contact.
Find a different partner. Record their name on your data sheet and simulate contact.
3. Use your pipette to place one drop of fluid on your slide at the “round 1” spot.
ROUND 2
4. Find a third, different, partner. Record their name and simulate contact.
Find yet another partner, with whom you have never before exchanged fluids,
record their name on your data sheet and simulate contact.
5. Use your pipette to place one drop of fluid on your slide in the “round 2” circle.
ROUND 3
6. Find a fifth, different, partner. Record their name and simulate contact.
Find a yet another partner, with whom you have never before exchanged fluids,.
Record their name on your data sheet and simulate contact.
7. Use your pipette to place one drop of fluid on your slide at the “round 3” spot.
CAUTION!
Glass is fragile.
Do not tap your test
tube against your desk
or other hard surfaces!
TESTING
8. Place one drop of testing solution directly onto each of the drops of fluid on your slides.
Be careful to not to let the tip of the testing solution bottle touch your samples as this
might contaminate the solution
9. Record your results on your data sheet.
Results & Discussion:. Record both your own data and the class data. Answer the questions.
Contagion Lab
KEW 05/07
Name
Results: Data sheet
PARTNERS:
Round 1:
Round 2:
Round 3:
Name of 1st partner: ______________________ Name of 2nd partner: ______________________
Name of 3rd partner: ______________________ Name of 4th partner: ______________________
Name of 5th partner: ______________________ Name of 6th partner: ______________________
TEST RESULTS
Pretest:
________________________
Round 2: ________________________
Round 1: ________________________
Round 3: ________________________
CLASS DATA: Collect your personal data on the board. Record the class data when the tables are complete.
Total number
of infected
persons.
Maximum
possible
infections
Round 0
Round 1
Round 2
Round 3
1
4
16
32
Total
number of
students in
the room:
Discussion:
1. Answer question a or b:
a. I caught the disease during ROUND # _______ OR b. I was lucky and never caught the disease _______
2. If you were infected, you should be able to figure out which contact(s) gave you the disease. Check back with
your partners during the round in which you caught the disease. Record their identity or identities.
_______________________________________
3. Did everybody in the class become infected?
_______________________________________
_________________________________________________
4. If we did this experiment long enough, would everybody have become infected? _______________________
Why or why not? ________________________________________________________________________
______________________________________________________________________________________
5. Predict how many people are likely to be infected if another two-partner round is played. _________________
6. Could you tell just by looking at the test tube which people had tested positive? ________________________
7. Name two other viruses that can cause disease (not necessarily STDs) other than HIV:
_______________________________________
_______________________________________
8. List and describe three or more ways that the spread of HIV/AIDS can be prevented.
______________________________________________________________________________________
Contagion Lab
KEW 05/07
______________________________________________________________________________________
______________________________________________________________________________________
______________________________________________________________________________________
SLIDE LABEL MAT
Round 0
Before any
contact
Round 1
After two
contacts
Round 2
After four
contacts
Round 1
After two
contacts
Round 2
After four
contacts
Round 1
After two
contacts
Round 2
After four
contacts
SLIDE LABEL MAT
Round 0
Before any
contact
Round 1
After two
contacts
Round 3
After six
contacts
Name _________________
SLIDE LABEL MAT
Round 0
Before any
contact
Round 3
After six
contacts
Name _________________
SLIDE LABEL MAT
Round 0
Before any
contact
Name _________________
Round 2
After four
contacts
Round 3
After six
contacts
Name _________________
Round 3
After six
contacts
Discussion:
1. Answer question a or b:
a. I caught the disease during ROUND # _______ OR b. I was lucky and never caught the disease _______
2. If you were infected, you should be able to figure out which contact(s) gave you the disease. Check back with
your partners during the round in which you caught the disease. Record their identity or identities.
_______________________________________
write the name(s) of the
3. Did everybody in the class become infected?
_______________________________________
person(s)
here.
_________________________________________________
usually no
4. If we did this experiment long enough, would everybody have become infected? _______________________
probably yes
Why or why not? ___
Eventually everyone will probably make contact with
somebody who is positive. Also, once positive (having
an incurable disease such as HIV), always positive.
5. Predict how many people are likely to be infected if another two-partner round is played. _________________
6. Could you tell just by looking at the test tube which people had tested positive? ________________________
no
7. Name two other viruses that can cause disease (not necessarily STDs) other than HIV:
_______________________________________
_______________________________________
Cold virus, flu virus, human papilloma virus (HPV),
ebola, herpes, hepatitis, rabies, measles, mumps,
yellow fever, chicken pox, cow pox, small pox, & more!
http://www.tulane.edu/~dmsander/Big_Virology/BVDiseaseList.html
http://www.gpnotebook.co.uk/simplepage.cfm?ID=-1838481387
8. List and describe three or more ways that the spread of HIV/AIDS can be prevented.
Abstain (don’t do) from sex and needle sharing.
Be mutually monogamous (faithful to one partner).
Condoms. (Use condoms properly every time.)
Don’t share needles (for drugs, tattoos, etc.)
http://www.biology.arizona.edu/immunology/activities/AIDS2001/teachers.html virtual lab
http://www.biology.arizona.edu/immunology/activities/AIDS2003/teachers.html virtual lab
Contagion Lab
KEW 05/07
Contagion Lab
Teacher Notes
Setup:
Each student needs a
test tube with about 2 ml of fluid,
Most test tubes have tap water.
One or two test tubes have NaOH solution.
a dropper pipette
(Use the long, plastic, disposable ones - this stuff forms a precipitate and you don’t want to wash glass
eyedroppers!),
a label mat (one 1/4 of page 3 of this document),
a strip of waxed paper roughly 2 inches by 12 inches (Just unroll the waxed paper onto the paper cutter and
chop, chop, chop) and
a pair of goggles (Students must wear goggles in the presence of the fluids!)
Each period needs 4-6 test tube racks for the test tubes.
Each classroom needs several dropper bottles of phenolphthalein (C20H14O4) solution.
Special Notes:
Use clean test tubes or there will be many false positives. Test water and NaOH to be sure that phenolphthalein
will give desired results. Acidify water if necessary.
Students must watch reaction carefully. Sometimes you get a flash of hot pink, then everything precipitates and all
you can see is a clear drop again.
Try using music to keep kids moving along and to help them remember to record their contacts. Fun and romantic
midis such as Close to You, Only You, On the Wings of Love, It’s in His Kiss, etc. are available at:
http://www.niehs.nih.gov/kids/music.htm
You should have material safety data sheets for everything on file at your site, but here are links:
http://www.flinnsci.com/Documents/MSDS/OP/PhenSol.pdf
http://www.flinnsci.com/Documents/MSDS/S/SoHydroS.pdf
Extensions:
Use, or ignore, depending on your teaching goals, student level, and/or time constraints.
Abstain: Have some students not simulate contact and/or form mutually monogamous pairs.
Ask question: “OK, Everybody knew what was up with this lab so. . .why did you do it? You knew that
eventually your test tube would become ‘infected.’” Possible answers: “It was fun.” “Everybody else was
doing it.” “You told me to do it.” Segue into decision making.
Ask question: “Why does this lab use the verb ‘simulate contact’ instead of ‘simulate sex?’” Possible answers:
“There is more than one way to catch HIV.” [The answer the teacher is looking for. Review routes of infection.]
You will also probably get, “Because some people would crack up and act out!” [This is accompanied by a
pointed look at the class clown.]
Graph results: Graph number of positive tests over time. Note that there are usually fewer than the maximum
number of possible positive cases because some people with positive test tubes simulated contact with people
whose test tubes were already infected.
Virtual labs: See these links:
http://www.biology.arizona.edu/immunology/activities/AIDS2001/teachers.html
http://www.biology.arizona.edu/immunology/activities/AIDS2003/teachers.html