Demetris Abernathy, Angelina Banks, Dominique Liddell, Marcus Walters

Research QuestionWhich everyday item will have more bacteria on it?

Items such as:Computer MiceElevator ButtonCell PhonesBook Bags

HypothesisIf people use their everyday items more than ten times a day, then there will be more bacteria on those items than lesser used items.

What Is Bacteria?

The structure of a Prokaryotic Cell, which is the most

common bacteria cell.

Background ResearchThere are many types of bacteria. Before the invention of DNA sequencing technique, bacteria was classified by shapes and sizes, otherwise known as Morphology.

Background Research cont.Most of the bacteria needs oxygen to grow. It takes 20 to 30 minutes to reproduce. The following chart shows the reproduction of one bacterium cell, if none of the bacteria would die over the time span.

1 Hour........................83 Hours...................5126 Hours...........2.62x105

9 Hours.......... 1.34x108

10 Hours….... 2.68x108

11 Hours........ 5.16x108

12 Hours……. 1.03x109

ProcedureIn order to test the different objects first, we had

to swab the items with a moist cotton swab.Then we transferred the sample to a agar plates.Next, we let the plates sit for two days at 68 ̊ F.Lastly, we counted the colonies of bacteria and

recorded the data.

Materials1.Distilled Water2.Cotton Swabs3.Our Everyday Items4.Agar Plates5.Gloves

Materials Cont.PursesBook BagsCell PhonesTV RemoteTV “ON” ButtonElevator ButtonComputer MicePublic Restrooms Inside Door HandleDorm Restrooms Inside Door Handle

DataBrown Small White Yellow

Purse 1.4 5 2.6 2.8

Book Bag 3.7 113.3 2.3 7.7

Cell phone "OK" 0 0.29 0.5 0Cell phone Earpiece 0 1.24 0.14 1.24

Elevator Button 0 347 0 0Public Restroom

Boys 0 3 0 0Public Restroom

Girls 0 2 0 0Dorm Restroom

Boy 0.5 58.5 0 0.5Dorm Restroom

Girls 50 136 50.5 50

Computer Mice 0.75 18` 1.5 0

TV Remote 0 6 0 0

TV On Button 0 15 0 2

Colonies

Num

ber o

f Bac

teria

We discovered that our hypothesis was false. The computer mice were used more than ten times a day, but are used by the same people. The restroom and elevator buttons did prove to be true.

Conclusion The dorm computers were used more

than ten times but did not have as much bacteria on them because they are used by the same people all the time. On the other hand the elevator button and public restrooms are not used by the same people everyday and the people that use it may not wash there hands.

Further Investigation Some of our mistakes was that the agar plates were not air tight. The air-borne bacteria leaked into the plates and caused extra growth on the control and some other plates that weren’t even used.

Work CitedLaRosa, Liz. "Where can we find bacteria?". 6/18/09

<middleschoolscience.org>."Agar Plate". Wikipedia. 6/24/09

<http://en.wikipedia.org/wiki/Agar_plate>. http://guccigoods.com/wp-content/uploads/2008/03/

authenticate_gucci_handbag.jpghttp://dontblinkjustthinktech.files.wordpress.com/2008/03/

sprint-lg-rumor.jpghttp://www.ict-science-to-society.org/Pathogenomics/images/

bacteria_cell.jpghttp://images.tigerdirect.com/skuimages/large/targus-

TSB082US-T22-2315-ma.jpghttp://www.buzzle.com/articles/different-types-of-bacteria.html

Mrs. MorganMrs. ScottMs. BowerMs. Daphne

Questions?