1. Jenny Zack Grade 9

2.  The purpose of the experiment is to test the affects of anti-bacterial cleaner, another known household bacterial-killing product, mouthwash, and time on the growth and sustainment of bacterial handprints.

3.  Microbiome  182 species on the hand  Staphylococcus, Corynebacteria, Streptococcus, Escherichia coli, Myobacteria, and Haemophilus

4.  If the bacteria are treated with antibacterial cleaner and mouthwash, then they will be ineffective as identifiers.  If the bacteria are left out for three days, then they will multiply, and can be used as identifiers.

5.  12 Petri dishes  Tryptic soy agar  Easy Gel coliscan  18 sterile cotton swabs  3 Inoculating loops  Duct tape  Antibacterial cleaner  Mouthwash  Paper towels  Sterile surface  Incubator

6.  First, I made a tape square on the surface of a table. I then made multiple bacterial handprints within that square to let it sit for the weekend and see how time affects it.  Next, I made a bacterial handprint on a table’s surface and sprayed the table with antibacterial cleaner. I then wiped it with a paper towel and took three samples.  For the mouthwash group, this routine was repeated, but I wiped the bacterial handprint with mouthwash.  When making the control samples, I made a bacterial handprint and took three samples without treating it with anything.  For time, the same process was repeated, however the bacteria was allowed 3 days to sit prior to testing.  Lastly, I placed all nine petri dishes in the incubator at 26 degrees Celsius.  All petri dishes were taken out of the incubator after 3 days of growth.  When examining the samples, I counted the # of colonies and colony types. I distinguished colony types by color.  After I examined the petri dishes, I put them in the fridge to preserve them.

7.  Independent Variable: The way the bacteria is treated before being swabbed  Dependent Variable: The way the bacteria grows as a result of being treated  Control: The bacteria not treated with anything or left out for a period of time before being swabbed  Constant: The Petri dishes, agar, and temperature of the incubator

10.  The hypothesis was partially supported because despite the use of the antibacterial products and mouthwash, bacterial growth was comparable to the control samples.  Also, bacterial growth was greater in the time samples than the control.  Given the results it is inconclusive whether or not these bacterial handprints can be used to identify suspects

11.  Thank you for your attention  Please feel free to ask any questions!  Sources are on the following slide

12.  “Growing Bacteria.” Science Enterprises. N.p., n.d. Web. 29 Sept. 2011..  HomeScience. “How to Grow Bacteria.” Youtube. N.p., 15 Feb. 2010. Web. 29 Sept. 2011..  “Human Skin Has Many More Types of Bacteria than Previously Thought.” Medical News Today. MedPage Today Professional, 2007. Web. 25 Jan. 2012..  Madrigal, Alexis. “Your Leaving a Bacterial Fingerprint on Your Keyboard.” Wired. Conde Nast Digital, 2010. Web. 29 Sept. 2011..  Martinez, Edecio. “Your Germs Might Be as Unique as Your Fingerprints.” CBSNews. CBS Interactive Inc., 2011. Web. 29 Sept. 2011..  “Telltale Bacteria.” The Engineer. Centaur Media plc, 2011. Web. 26 Sept. 2011.. Thank you to everyone in the audience for listening to my presentation! I would be happy to answer any questions you may have about my project!