(a)
(b)
(c)
(d)
Figure 4: Representative hematoxylin and eosin-stained tissue sections of OCTs cold-preserved in the presence and absence of supplemental hydrogen. Histological analysis of OCTs was performed after 3 weeks of preservation in DMEM (a), DMEM with H2 (b), UW solution (c), and UW solution with H2 (d). Scale bar, 50 μm.