Cell replication and protein renewal in post-ischemic mouse kidney analyzed with double labeling with BrdU, analyzed as 81Br- and 15N-leucine. (a,b) Wide-view parallel quantitative mass image of (a) 12C14N- and (b) 81Br-. The 81Br- label indicates a cell with replicated DNA. Field: 100 μm × 100 μm (256 × 256 pixels); acquisition time 2 min. (c-e) Higher-resolution parallel images of the boxed regions in (a,b) for (c) 12C14N-; (d) 31P-; (e) 81Br-. The 31P- image enables identification of other cells with unreplicated DNA. Field: 23 × 23 μm (256 × 256 pixels); acquisition time 60 min. (f,g) Parallel quantitative mass images for (f) 12C14N- and (g) 12C15N-, from which protein renewal is calculated. Field: 23 × 23 μm (256 × 256 pixels); acquisition time 10 min. (h) Quantitation of protein renewal in replicating and non-replicating cells. Cy, cytoplasm; NQ, nucleus of non-replicating cells; NR, nucleus of replicating cells.