Extended Data Fig. 1: Influence of buffer, pH, temperature and detergent on antigen retrieval.

a, Whole pancreatic lobules were treated for 16 h with the indicated buffers containing 4% (wt/vol) SDS at the indicated temperatures. Shown are representative stainings for Krt19 (pancreatic ducts). Blue lines indicate the minimum temperature above which staining was observed; red lines indicate the maximum temperature above which sample damage was noted. Crosses indicate sample loss. b, 3D view of a pancreatic lobule after cardiac perfusion with dextran-FITC (DexFITC) before and after FLASH reagent 1 treatment (scale bars: 150 µm). c, Comparative whole pancreas immunolabeling for keratin 19 (ducts), C-peptide (islets of Langerhans) and amylase (acinar cells). Samples were incubated at 54 °C with borate alone (left column) and borate with the indicated detergents (all 8% (wt/vol)) without urea. All scale bars: 300 µm.