Can Tide GAIN All the Prize?

Photo © 2009 Flickr, Pixel Drip

High school student, Dao Quan Lin, wondered how effective liquid laundry detergents were at destroying the bacteria that can grow on our clothes - specifically Serratia marcescens. There are a bunch of detergents out there so, to narrow down his testing field, Dao began his project with a survey of local laundry mats to determine which brands were the most popular. His results showed that Tide, Gain, and All were the popular choices. 

To complete the project, Dao needed the following materials - a sterile Petri dish, agar, sterile filter paper, detergent samples, and a place to incubate the samples. After 24 hours, he checked the results and measured the zones of inhibition. [NOTE: If you don't know what that is, Science Buddies has a great informational article/tutorial about it!] We know the moms at your middle school will be interested to know the results - everyone wants bacteria free clothing!