Differentiation of Staphylococcus Phenotypes Using Dielectrophoresis

Dielectrophoresis is an analytical technique which involves electroosmotic flow, electrophoresis, and dielectrophoretic force. These factors, when in correct proportions for a given analyte, allow for dielectrophoretic trapping, otherwise known as dielectrophoretic capture. Non-uniform electric fields are required for this phenomenon, and the device in this trial used to induce such an electric field was a gradient insulator-based design. Similar devices have been previously used to separate or identify a wide variety of analytes within solution. Much of the previous work has been focused on the differences in dielectrophoretic trapping between strains of bacteria, whereas this experiment focused on the differentiation of phenotypes within a single bacterial strain, Staphylococcus aureus isolate 35984. A control sample was tested, as well as a sample heated at 70oC for 15 minutes to induce phenotypic changes. The control sample was found to exhibit dielectrophoretic capture at a given gate at a potential of 800V and higher, whereas the heated sample was not observed to capture at any potential in this experiment, which reached a maximum of 1200V. Notably, neither of the samples were found to capture at or below 600V. The results of this experiment were encouraging, though it is worth noting that several experimental trials failed to produce any noteworthy results. As such, the procedure of this experiment should be refined to increase reproducibility of results.