Produced by the Department of Media Relations & Publications

The Life You Can't See: Students Explore Invisible World of Microbes on Campus

January 25, 2011

Biological Sciences Professor Haiping Cheng (far left) with students of his Experimental Microbiology course.

Ever wonder what's living on your computer keyboard? A group of students in Professor Haiping Cheng's microbiology course conducted an experiment to determine just that, and what they found surprised them.

"The class came up with a unified theme about food contamination," said Professor Cheng, "and wanted to know the amount of bacteria on our computers on campus, so they devised an experimental protocol for the study."

The Experimental Microbiology (BIO 331) students tested microbial growth on computers in the Leonard Lief Library and the ITR Center by touching the keyboard's 'R' button—which is thought to be more frequently used than others—with one clean finger, followed by one dry and one wet Q-Tip. Students then pressed and printed their fingertips onto Petri dishes that were incubated for two days to allow the growth of bacteria.

"You can fit almost a million microbes on the head of a pin, so imagine how many can fit on a computer key," said senior and biological sciences major Wilfredo Valentine, who plans to become an M.D. "It's imperative to know that microbes are all around us, and it's good to get a grasp of how we interact with them." Valentine is a Louis Stokes Alliances for Minority Participation (LSAMP) scholar and past intern at Albert Einstein College of Medicine.

He says that he and many of his classmates were surprised by the results of the study, which showed that the keyboards did not yield as many microbes as one might think. The 'R' key actually contained fewer microbes than people regularly have on their hands. Also, some students reported finding more bacteria on their hands after having washed them. They suspected that the source of the bacteria could be the bathroom's hand dryers, which blows more air (and airborne bacteria) on hands even after they are washed.

"This method of inquiry allowed students to integrate what they learned in class and apply that to real-life questions. It further stimulated their interest in the class," said Professor Cheng.

Another student in the course, Samsiya Ona, was excited for this opportunity to gain hands-on experience through the study. "Dr. Cheng was one of the best professors I've ever had," says Ona, who is also an LSAMP student and Presidential Scholar, as well as a member of Phi Beta Kappa, Golden Key Honour Society, and the Lehman Scholars Program.

"This course taught me a lot about microbiology, and I'm looking forward to becoming an M.D. and conducting research, looking specifically at infectious diseases in tropical areas." Ona hails from Togo, West Africa, where infectious diseases like malaria are still a major problem.

"It was a small class that included a lot of the people I started my pre-med journey with," said Valentine, who plans to pursue an M.D. / Ph.D. and hopes to work in orthopedic surgery one day. "The course made it easy to digest the information." The results of these studies were summarized and presented in a poster, which is displayed just outside the cafeteria, alongside another poster created by the other section of the course. Students in the other section created a poster reflecting their research on food contamination and what can be done to reduce the risk of contamination during the processing of food.


Food Contamination and You

Microbes Around You