PROJECT SUMMARY This administrative supplement will be used to replace a centrifuge that is essential to the project funded by the parent award on mechanisms of mitochondrial mutation rate variation. The project relies on high-purity isolation of mitochondria and chloroplasts from large quantities of tissue, using high-speed gradient centrifugation. The NIH-funded equipment that was intended to be used for this project experienced unforeseen damages that rendered it inoperable, and the requested replacement will be used to complete project goals over the 4+ years remaining on the parent award.