As much as I understand, Kabuto said that he was unable to revive Shisui because he couldn't find anything belonging to him. His right eye was crushed by Danzo while the other was then implanted into a crow that was inside Naruto which was later summoned and destroyed by Itachi. Shisui's corpse was also not to be found since Shisui somehow managed to 'erase his existance'.
However, if we can remember Danzo not only had Shisui's eye implanted during his prime but also had Shisui's right arm. That would explain why he was able to successfully use 10 sharingans without much exertion. Another proof of this is that Ao noted that the chakra in Danzo's right arm was familiar and considered it to be that of Shisui's. The last time we saw Danzo's body was with Obito, when he wanted to obtain the eye but then realized that Danzo had got rid of it.
So my question is, Why couldn't Kabuto obtain some DNA through Shisui's right arm(whatever was left of it) that was still attached to Danzo?