The Great Necktie Debate!

My students have been doing research and data collection of microbial populations on neckties worn by their faculty. The project is described below in detail. We are currently still collecting and analyzing data. I imagine this phase will take approximately one more week before we transition into the actual analysis of findings and writing up the report. This is one of those awesome projects that will never be able to be replicated, unfortunately, but it has really required true meaningful work on the part of my students and I have been so impressed with their abilities and developed techniques when dealing with microbiology.

If you are interested in the process or the findings, please contact me.

Project-Based Learning Title: The Great Necktie Debate

Grade: 10th

Project idea: Students have been charged by a male faculty, who happens to dislike wearing ties on a daily basis, to see if there is a “health risk” to wearing ties as they contain a lot of microbes. This research spans all three sections of regular biology and these students have taken this charge and decided that they will research it.

The students in all three sections used the collective Google platform for uniform access to information. The students researched the historical purpose of the necktie, they have researched different career paths that have done away with idea of wearing a tie because of health concerns (dentists, doctors, etc…), the students designed the experiment and performed the experiment over the course of multiple weeks, students analyzed the data, and, students reported out the data in the form of a formal journal article.

(My students are working on their scientific understanding and writing. Therefore, this DQ was formulated in the spirit of a hypothesis) If neck ties are swabbed for bacterial growth then large quantities of bacteria will be observed because neckties are worn for many years and rarely cleaned and therefore contain an excessive amount of microbes.

microbial growth (microbiology), bacterial plating techniques (microbiology), bacterial species identification (microbiology)

Major Products:

  1. Swabbed ties of all Upper School male faculty and administrators
  2. Plate all tie bacteria on nutrient agar
  3. analyze plate growth and re-plate a colony for a pure culture
  4. Use excel to analyze data and create meaningful infographics
  5. Write a formal scientific paper describing research and explaining results
  6. Publish paper in Collegiate School Journal of Microbiology

Public Audience: US faculty; US Administrators; Alaina Campbell – Department of Biology, VCU; Dr. Berry Jacques – Tufts Medical University





The Great Necktie Debate

It is difficult to determine exactly when the necktie first made its appearance, and exactly where. Some sources state that the necktie first appeared in the Chinese army, over 1000 years ago (Ashley, O., 2013). Other historians agree that the necktie appeared in the 17th century, during the 30-year war in France (Hendrick, 2013). Whatever the origin, the fact is that neckties have been a fundamental accessory for predominantly male fashion for centuries.

Though adding to the air of professionalism, there is potential for the necktie to be harboring potentially dangerous pathogens, especially in professions that have excessive contact with children or the sick. A study performed by researchers at the New York Medical Center of Queens found that nearly 50% of neckties worn by physicians harbored bacteria that can cause disease (Science Daily, 2004).

If neckties do harbor abnormal amounts of potentially pathogenic microbes, should faculty members in a school be required to wear them?

You have been hired by Virginia Commonwealth University’s Department of Microbiology to determine if neckties worn in a 9-12 school setting have an excessive amount of microbes contained on them. The results of your findings will be published in the Collegiate School’s Journal of Microbiology and you will be asked to present these findings at a national high school science conference.



The students are wrapping up their scientific method and process of science units, as well as moving quite quickly through their microbial pathogenesis unit. Prior lab work for these classes included: pouring agar plates, streaking plates with populations of E. coli, looking at antibiotic resistance of E.coli, looking at antimicrobial properties of E. coli and B. cereus with respect to common household cleaners, analyzing CFU (colony-forming units) growth on Petri dishes, practice using an incubator and practice using an autoclave.


I introduced this unit by playing this video, found in the beginning of this PowerPoint. On the video, a well-respected male faculty member in the upper school was interviewed and addressed his concerns about the potentially hazardous nature of wearing a necktie every day and he asked the students to gather data to support his hypothesis.


Students started by creating a google document shared between all three classes. The students volunteered themselves for various duties throughout the research. The students split into the following teams: Research & Problem, Hypothesis, Materials & Methods, Survey Team, Tie Swabbers, Petri Dish Inoculators, Petri Dish analyzers, Data analysts, Excel Professionals, and each student would contribute to the Conclusion and the formal writing process.

  • Research & Problem – students began by doing extensive research on the necktie and it’s historical purpose in male dress
  • Hypothesis – students created a working hypothesis in an If, then, because format (it should be noted that this took quite a long time for the students to agree on a workable hypothesis – good collaboration and communication of ideas)
  • Materials & Methods: determined how they were going to sample tie microbial growth and what materials they would need to do so. Students decided to sample all US male faculty and all administrators and compare the tie growth between the two divisions. Students decided that each tie swabber would need to sample with a partner who’s job was to gather data for the survey that correlated with the sampling work.
  • Tie Swabbers: students met in the teacher’s classroom each morning before school to gather materials, determine which teachers needed to be sampled, and would go out and sample as many ties as possible. The sampling process took two weeks of morning time.
  • Survey Team: students created a survey to correlate with the microbial data collected. The students asked faculty members how old their tie was, how often it was cleaned or dry cleaned, whether they liked wearing ties and whether they believed ties should be mandatory or not.
  • Petri Dish Team: this team was responsible for removing the petri dishes from the incubator, analyzing and recording the growth on the collective google sheet. After analyzing growth, these students were responsible for re-plating an original strain onto a new petri dish to isolate pure cultures of bacteria. The re-plate would go back into the incubator for 24 hours, the original plate would be sealed and placed in the fridge. After 24 hours, the re-plate was taken out of the incubator, analyzed and recorded, sealed and placed in the refrigerator.

Before beginning the research, the students composed an email to the senior administrative team requesting permission to perform the study. After receiving permission from the administrative team, the students then created an email for the faculty explaining what their purpose was, the research needed and asked the faculty for their help by allowing the students to swab their ties.

After collecting the data students worked collectively to write the formal laboratory report and literature review to present their results to the faculty and administrative team.


Collective Google Doc

Tie Survey

Tie Data

Petri Dish Pictures

Photos of Student Work:

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