Theoretical Experiment
Justice Samuels
Microbiology-McCarthy
Problem statement
The electronic devices used on a daily basis (e.g., smart phones, tablets, laptops, desktops, remote controls, smart phone and tablet cases, etc.) harbor microscopic bacteria and fungi that can cause illness such as colds, influenza, MRSA, norovirus, and staph (Abrams, 2017; Al-Abdalall, 2010). There are a number of commercial products on the market specifically designed to safely clean and sanitize electronic equipment without damaging it.
Hypothesis
Not all electronic device sanitation products are created equally. Some are more effective than others at killing bacteria, fungi, and other pathogens (“Household Micro,” 2014).
Materials
Gallon size Ziploc bags (for disposal)
Magic marker Petri dishes
Sterile swabs Sterile tryptic soy agar (TSA) bacterial growth media
Safety goggles Disposable gloves
Experimental Design/Method
The controlled or dependent variable is the electronic device being tested. The manipulated or independent variables are the types and brands of commercial electronic sanitizing products being tested. Two different cleaners are used for this experiment. NOTE: This experiment works best on electronic devices and cases that have not been cleaned or sanitized in several days (“Household Micro,” 2014).
Procedure
For protection during the handling of bacteria, wear safety glasses and disposable gloves (“Household Micro,” 2014). Six petri dishes are used for this experiment. Two petri dishes are used to test the bacteria found on the device (one petri dish for the front surface, and one petri dish for the back surface or case); two more petri dishes are used to test the bacteria found on the device after sanitizer A has been applied to the front and back surfaces of the device (one petri dish for the front surface, and one petri dish for the back surface or case); the final two petri dishes are used to test the bacteria found on the device after sanitizer B has been applied to the front and back surfaces of the device (one petri dish for the front surface, and one petri dish for the back surface or case). Use the magic marker to label each petri dish with the date and the source of the swab as follows:
Petri dish 1: (Date) Dirty Front Petri dish 2: (Date) Dirty Back
Petri dish 3: (Date) Clean Front A Petri dish 4: (Date) Clean Back A
Petri dish 5: (Date) Clean Front B Petri dish 6: (Date) Clean Back B
Separate sterile swabs are used to obtain bacteria samples from the electronic device and case, when applicable. The swabs are segregated to prevent cross-contamination, and each swab used has its own petri dish. The first swab is rubbed on the front surface of the electronic device at least 30 times; then the swab is rubbed on the (TSA) bacterial growth media inside the petri dish labeled (Date) Dirty Front, and the lid is placed on top of it (“Household Micro,” 2014). The second swab is rubbed on the rear surface or case of the electronic device at least 30 times; then the second swab is rubbed on the (TSA) bacterial growth media inside the petri dish labeled (Date) Dirty Back, and the lid is placed on top of it (“Household Micro,” 2014). To encourage rapid bacteria growth, place the petri dishes in a warm location, making sure they are in an upside down position; takes approximately five days for bacteria growth to appear (“Household Micro,” 2014).
Use Sanitizer A to clean a partial area of the electronic device on the front and back and allow those areas to dry. NOTE: Since the experiment is comparing and testing two different sanitizers, only a partial area of the electronic device surface is going to be sanitized by each product. After the sanitized electronic device surfaces have dried, separate sterile swabs are used to obtain samples from both sides of the electronic device, taking care again to keep the swabs segregated to prevent cross-contamination; each swab used has its own petri dish (“Household Micro,” 2014). The first swab is rubbed on the front surface of the electronic device at least 30 times; the swab is rubbed on the (TSA) bacterial growth media inside the petri dish labeled (Date) Clean Front A, and the lid is placed on top of it (“Household Micro,” 2014). The second swab is rubbed on the rear surface or case of the electronic device or case at least 30 times; the second swab is rubbed on the (TSA) bacterial growth media inside a separate petri dish labeled (Date) Clean Back A, and the lid is placed on top of it (“Household Micro,” 2014). To encourage rapid bacteria growth, place the petri dishes in a warm location, making sure they are in an upside down position; it takes approximately five days for bacteria growth to appear (“Household Micro,” 2014).
Use Sanitizer B to clean a partial area of the electronic device on the front and back and allow those areas to dry. After the sanitized electronic device surfaces have dried, separate sterile swabs are used to obtain samples from both sides of the electronic device, taking care again to keep the swabs segregated to prevent cross-contamination; each swab used has its own petri dish. The first swab is rubbed on the front surface of the electronic device at least 30 times; then the swab is rubbed on the (TSA) bacterial growth media inside the petri dish labeled (Date) Clean Front B, and the lid is placed on top of it (“Household Micro,” 2014). The second swab is rubbed on the rear surface or case of the electronic device or case at least 30 times; the second swab is rubbed on the (TSA) bacterial growth media inside a separate petri dish labeled (Date) Clean Back B, and the lid is placed on top of it (“Household Micro,” 2014). To encourage rapid bacteria growth, place the petri dishes in a warm location, making sure they are in an upside down position; it takes approximately five days for bacteria growth to appear (“Household Micro,” 2014).
Data Collection
Approximately five days after the samples have been taken, bacteria should appear in each of the six petri dishes to varying degrees. For protection during the handling of the petri dishes, wear safety glasses and disposable gloves (“Household Micro,” 2014). Do not open the petri dishes as the concentration of bacteria contained within is exponentially higher than the levels found on your device and could cause serious illness (“Household Micro,” 2014). To document the differences in bacteria growth, photograph the petri dishes individually and in pairs (e.g., Dirty Front/Dirty Back; Clean Front A/Clean Back A; Clean Front B/Clean Back B). Once the results have been fully documented, seal the petri dishes in Ziploc bags to contain the smell and kill the growth of the bacteria; discard the sealed Ziploc bag in an outdoor trash receptacle (“Household Micro,” 2014).
Possible Outcomes
The bacteria samples obtained from the electronic devices before they were sanitized may show similar amounts of bacteria on the front and rear surfaces, or more bacteria on one surface than the other (“Household Micro,” 2014). A comparison of the bacteria levels found after sanitizer A and sanitizer B were used to clean the electronic device may show comparable levels of bacteria, meaning each product works similarly well; one sanitizer may have lower bacteria levels, meaning it is more effective than the other product. If the device being used for the experiment has a case (e.g., smart phone or tablet), the level of effectiveness of sanitizers on cases may be affected by the type of materials the case is made of: hard plastic, soft plastic, cloth, etc.
Conclusions
This is a valuable experiment to raise awareness of the hidden dangers found within electronic items used every day. There are reasonable concerns regarding the cleanliness of shared devices such as office phones and office computers; however, the biggest health threat may be found in devices within the home (Bhoonderowa, Gookool, & Biranjia-Hurdoyal, 2014).
It is important to regularly clean and sanitize electronic devices using sanitizers that have been proven to be effective.