Board Thread:Naruto Discussions/@comment-12509038-20140806073433/@comment-3568954-20140806113733

Uchiha913 wrote: I know that Obito had Hashirama cells in life but I doubt he had it when he gave his chakra to him this time.

a shinobi's chakra is influenced by stuff like DNA so over the years his chakra has likely gained a fragment of hashirama's