Acute renal ischemia (induced in C57BL/6 mice by cross-clamping the renal artery for 30 minutes), followed by reperfusion, has been extensively investigated as a model of acute kidney injury. Similar to humans, it is increasingly appreciated that renal recovery may not be complete; it may lead to chronic tubulointerstitial damage. In the study that is shown, (reproduced from [87] with copyright permission), the contralateral kidney was removed at the time of ischemia induction and fibrosis was detected by Masson trichrome staining 30 days later.