To teach the girls from the Women in Science Day Camp about bacteria that can be engineered to perform certain functions, we designed an activity which uses bacteria to detect pollution in water. When a plasmid containing the arsenic dependent promoter (part BBa_J33201) and the ribosome binding site, ATF1 gene, and double terminator construct (part BBa_J45199) in introduced into E. coli, isoamyl alcohol will be converted into isoamyl acetate when arsenic, or any other heavy metal, is present. Thus, water contaminated with heavy metals will smell like bananas. When a plasmid containing the tetR promoter, ribosome binding site, BSMT1 gene, and the double terminator (part BBa_J45120), salicylic acid will be converted to methyl salicylate in the presence of the antibiotic tetracycline. Thus, water contaminated with antibiotics will smell like wintergreen. The cloning of the banana arsenic construct was not complete by the time the campers arrived so the pollution detecting E. coli could not be used. Instead, cultures of non-transformed E. coli were prepared. Methyl salicylate was added to samples that were 'contaminated' with antibiotics and isoamyl acetate was added to samples that were 'contaminated' with heavy metals. This set up allowed the campers to perform a safe sniff test without any actual contaminants.

We thought it was unlikely that 5-7th graders would have a firm understanding of how DNA works based on what they’ve most likely learned in school so far. In order to help them grasp the concept in a hands-on way that’s fun and easy, we had them build their own codon out of colorful paper pieces representing deoxyribose, phosphate groups, and nucleotides. All of the pieces were cut out ahead of time to save time and make the project more enjoyable for the girls, and a sample was built for them to use as a guide and to help us explain the different parts of DNA more visually as they constructed their own. While they were putting their codons together, we explained how DNA works as a code 'read' by bacteria to make proteins and what the different combinations of nucleotides might mean. To make things simpler, we used 'instructions' as a metaphor: you can't build a bike that works if you don’t know how to put the pieces together. The girls got to take their codons home as a reminder of everything they learned.