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Fig. 2. Embryonic lens hypoxia visualized using the bioreductive marker
pimonidazole. E17 lenses were incubated in pimonidazole in vitro
(AC) in solutions equilibrated with 21%, 2% or 0% O2.
Formation of pimonidazoleprotein adducts was visualized
immunocytochemically (see text for details). In 21% O2 (A), no
adducts were detected. However, adducts were detected in the cortex of lenses
incubated in 2% O2 (B), and intense cortical staining was present
in lenses incubated in 0% O2 (C). In vivo treatment with
pimonidazole (DF) resulted in strong cortical immunostaining throughout
development. When pimonidazole was omitted from the intraocular injection
solution, no immunostaining was observed (G), confirming the specificity of
the pimonidazole antibody. Scale bar, 250 µm.