For purification of podocytes from adult kidneys we used a similar strategy, only we first isolated glomeruli using a sieving method, allowing us to start with a dramatically enriched podocyte population. Kidneys were isolated in order BEZ235 ice-cold PBS, bisected, and the medullary region was removed using a scalpel. The remaining cortical region was finely minced using a razor blade, placed into a solution of PBS/1.0% collagenase and incubated at 37uC for 15 min. The solution was vigorously triturated every five minutes. An equal volume of ice-cold 5% FBS/PBS was added and the mixture was filtered through a 100 mm mesh. The flow-through was collected, triturated vigorously and refiltered through a 100 mm mesh. This step was repeated twice. To collect the glomeruli, the flow-through was filtered using a 40 mm mesh. The glomeruli trapped in the filter were isolated by turning the filter over and rinsing with ice-cold 0.1% FBS/PBS. The collected glomeruli were vigorously triturated and re-filtered through 40 mM mesh. This process was repeated three times. After the final collection, the glomeruli were pelleted, washed with ice-cold PBS and resuspended in 0.5% trypsin, and incubated at 37uC for 10�C15 min. During incubation, the glomeruli were triturated every five min. A portion of the sample was observed under a microscope to monitor cell dissociation. After incubation, ice-cold 5% FBS/PBS was added, the cells were pelleted, washed three times with ice-cold PBS and filtered before FACS analysis. This study was carried out in strict accordance with the recommendations of the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. The protocol was approved by the Cincinnati Children��s Research Foundation Institutional Animal Care and Use Committee . Ionizing radiation is ubiquitous in our environment and has many beneficial medical and industrial applications. However, IR also carries potential hazards for human beings, particularly for bone marrow with the ability of rapid self-renewal . In addition, radiotherapy, as a commonly used treatment for various tumors, induces severe toxic effects on normal healthy tissues due to its non-tumor specificity .