DescriptionChlamydia trachomatis is an obligate intracellular microbe that is responsible for trachoma and chlamydia in much of the developing world, but is difficult to manipulate due to its biphasic developmental cycle. The current protocol for transforming Chlamydia trachomatis is a very time consuming process, yielding limited numbers of successful transformants only after multiple passages of infection which can take up to 48 hours per passage, while also requiring a highly time consuming purification process for elementary bodies. Chlamydia trachomatis’ genetically conserved and faster growing cousin, Chlamydia muridarum (MoPn) was used as a model organism to test the influence of elementary body (EB) purity and concentration of plasmid on transformation efficiency. Ultimately, the experimentation was inconclusive; higher amounts of plasmid in the initial transformation did not yield a higher number of transformants nor yield them in earlier generations when compared to the control groups. Furthermore, the purity of infectious elementary bodies (EBs) were not essential for transformational competence; both ultra-purified EBs that were isolated via a density gradient and partially purified Chlamydia muridarum displayed successful transformants. Further experimentation would be needed with higher sample sizes to ensure statistical significance, and trials on Chlamydia trachomatis itself would have to be performed to ensure consistency across both species. Finally, trimethoprim, banzal-N-acylhydrazones (BAH), and other antibiotics should continue to be screened as alternative selective agents due to their differences in mechanisms of action.