Rat NRK stably expressing RFP targeted to mitochondrial matrix imaged at the M phase of the cell cycle. This image is a z-stack from a living cell collected on a Zeiss 510 LSM confocal using a 63X 1.4NA objective. There is a related z-series of a cell in G1/S transition. The stable mito-RFP expressing NRK cell line was prepared by Kasturi Mitra.