This purpose of this experiment was to study the effects of the heavy metal aluminum on Escherichia coli K-12. Aluminum is an adjuvant in some immunizations, and E. coli is found in the gastrointestinal tract of mammals. It was hypothesized that as aluminum concentrations and pass numbers were increased, E. coli would experience more cell death. The effects were determined by increasing the concentration of aluminum (2 microM - 1024 microM) in an attempt to create aluminum mutants. In order to determine the growth effect after continued exposure to aluminum, replica plating on 1024 microM aluminum was performed creating passes 0 through 15. Minimum inhibitory concentration tests were done to determine specific aluminum concentrations of toxicity, and a modified minimum bactericidal concentration test was performed to observe the concentration of aluminum that killed E. coli. The data was analyzed statistically using a one-way and two-way Analysis of Variance (ANOVA) test. Statistically, there is a significant difference in E. coli growth in the presence versus the absence of aluminum at 16 mM and 25 mM. For all aluminum concentrations less than 25 mM, there is no significant difference in E. coli growth from early passes (pass 0 - pass 8) when compared with later passes (pass 8 - pass 15). Also, there is no significant difference in growth at low aluminum concentrations when compared to high aluminum concentrations. Phenotypically, an atypical pigmentation was observed in experimental groups when compared with control cells. Currently, only 62% of E. coli genes have designated functions. Therefore, it is feasible that one or a combination of the remaining genes could function to decrease, eliminate, or adapt to exogenous substances like aluminum.