In this lab, two closely related bacterial cell types are transformed with two color-generating plasmids. This content is relevant to genetics and inheritance lessons, molecular biology, and DNA expression units. Sterile technique and microbial culturing are emphasized in this streamlined and effective alternative to more common transformation protocols.The engineering concept of “chassis selection” gives this lab a context beyond a simple exploration of the transformation technique. Because the pigments that are generated by the plasmids are visible to the naked eye, it’s easy to discern if the expression differs between the two chassis, and the data can be analyzed both quantitatively and qualitatively. Students can design further experiments to understand what differences between chassis that might explain their data.