In this project Nuclear Engineering students are exposing cells to various concentrations of uranium, measuring its intracellular uptake, and evaluating its toxicity using the clonogenic and other assays, such as the Comet assay, to measure the extent of DNA damage.  The clonogenic assay measures the capability of cells that were exposed to uranium to reproduce.  The Comet Assay also known as Single Cell Gel Electrophoresis is used to measure single and double DNA strand breaks. Briefly, in this assay, an electric current is applied to a buffer solution (neutral yields double strand breaks and alkali yields both single and double strand breaks) in which agarose slides, previously plated with individual cells whose nuclei have been extracted are positioned.  Broken DNA fragments are ejected from the cell nucleus as a result of the electric field.  These migrate outside the cell.  Slides are read by fluorescent microscopy, and a LUCIA  image analysis system reads parameters such as head (amount of DNA in the nucleus) and tail (amount and distance of ejected DNA) and gives a statistical analysis of the

of our students in the laboratory is shown on the right.  The cell had incorporated a porphyrin molecule and was then exposed to UV radiation which apparently caused the damage to DNA.  This project is being carried out as a collaborative study with Rotem Industries.