Confocal microscopy whole-mount images of rat islets after 24 h culture under low oxygen (0.01 mM) without (A–D), with OxySite (E–H) or under standard oxygen (0.2 mM, I–L). Islets were stained with oxygen sensitive hypoxyprobe (green, A, E & I), insulin (yellow, B, F & J), and glucagon (magenta, C, G & K). Composite image of all stains (D, H & L). Scale bar = 50 μm.