Figure 2.

3D quantification of endocrine cell composition in the human islet. A: A large-scale capture of a tissue block immunostained for insulin (green), glucagon (cyan), somatostatin (blue), and a pan-endocrine cell surface marker (HPi1; red). Scale bar: 500 μm. B: Fluorescent signal processing of z-stack by binary conversion. (a) A representative slice of three islets (boxed in A) showing four channels merged. (b) Pan-endocrine. (c) Insulin. (d) Glucagon. (e) Somatostatin. C: Quantification of volume in 3D. (a) 3D surface rendering of pan-endocrine fluorescent binary signal used to identify islet boundary. 3D fluorescent signals for pan-endocrine (b), insulin (c), glucagon (d), and somatostatin (e). Scale bars: all 100 μm. D: (a–e) Optical slicing from top to bottom of islets showing pan-endocrine and three hormone fluorescent markers. E: Percentage of islet volume constituted by β-cells (insulin, green), α-cells (glucagon, cyan), and δ-cells (somatostatin, blue) was quantified. Five islets of different sizes were selected for each donor for quantification. yo, year-old.