Title: Rate of Growth of Bacteria

Question: Which disinfectant kills the most bacteria. Pine sol, Pledge, Lysol

Purpose: To see what disinfectant we should use to kill off the most bacteria.

Background:All of these disinfectants say they kill 99.9 percent of germs and bacteria, but do all actually work the same? Phenols are produced by coal distillation and are commonly found in mouth washes, scrub soaps, and surface disinfectants. They function by destroying cell membranes and denaturing proteins. Chlorine functions by oxidizing proteins and nucleic acids.(Beautiful Dragons) Iodine kills a wide range of bacteria, including the hard-to-kill tuberculosis germ and one ounce can kill all of the germs in 7,800 gallons of water.(ehow disinfectants) The active ingredients in Lysol disinfectant spray are Alkyl (C14, C12, C16), Dimethyl Benzyl Ammonium Saccharinate. Alkyl Dimethyl Benzyl Ammonium Saccharinate is a slight toxin used to kill microbes.It is the main ingredient in killing off microbes even though there is very little in the product.(ehow lysol)

Plan: We plan to gather various disinfectants, and using them on cultured bacteria in petri dishes to see how effective each disinfectant that all claim they can "kill 99.9% of bacteria". Then after we use the disinfectants on the bacteria we will take a swab from each dish, turn the swab of bacteria into slides, and then view them underneath a microscope to analyze how much bacteria was killed. We will then record the data.

Summary: After going through these steps we hope to find out which disinfectant kills the most bacteria to avoid illness.

Procedure: First, we took cotton swabs and swabbed the desks. Next, we put the bacteria in the petri dish. Finally, we recorded how much bacteria grew each day.

Hypothesis: If we spray disinfectant on the bacteria, then the bacteria will die.

Materials: Lysol disinfectant spray, Pine sol, Pledge, Petri dish, Cultured bacteria, microscope, cotton swabs.

Analysis: Out of the five disinfectants, Pine sol worked the best. Lysol air disinfectant was the worst.

Conclusion:Our Hypothesis was correct, which was if we spray disinfectant on the bacteria, then the bacteria will die. Pine sol did work the best. Lysol air disinfectant was the worst.

Limitations: Weekends, and snow days were our only limitations cause we were not there to record the data.

How are you going to quantify your data? (Mr. Kerwin)
Are you getting the bacteria from the same place and where? (Berry)
What brands of disinfectants are you going to use? (Rpunke)
how are you going to determain how much bacteria was killed?<the percentage> (Agner)
Shouldn't the purpose be the same thing as the background? (David Sabotta)
How much of the spray are you going?(J-Urban)
Certain disinfectants kill certain bacteria so results may be different if you have different bacteria in the dishes Michael Phillips
How are you going to controll all of the different types of bacteria?(iteubel)
"Disinfectants." Disinfectants. N.p., n.d. Web. 29 Nov. 2012.

Bramble, Laura. "Disinfectants That Kill Bacteria." EHow. Demand Media, 05 June 2010. Web. 29 Nov. 2012. http://www.ehow.com/list6593700_disinfectantskillbacteria.html

Baldwin, Anya. "LysolNeutra Ait Ingredients". Ehow. Demand Media, inc. Thursday 29, November 29 2012. http://www.ehow.com/info_8354431_lysol-neutra-air-ingredients.html

% of Bacteria - Control

Graphs: Bacteria Spreadsheet-Control
Bacteria Spreadsheet- Experiment