You can't use Izanagi without Senju cells...
Edit: You also can't use Izanagi without losing sight in the eye with which you cast it
We already know, and it is 100% that Madara gave Nagato HIS eyes, not a set of spares, not just one, but BOTH of his eyes
Sick of people saying Madara used Izangi to survive because we know he only gets Senju cells post fight not before or during. Even if he got them during I doubt he'd be able to utilize them right away, the whole thing is preposterous
However, I will admit its a possibility he cast a genjutsu on Hashirama. But did anyone actually notice the way he stabbed Madara? For 1 thing it wasn't through the heart or anything so it wouldn't be a definite kill, and also the way he stabbed him from behind was a nice parallel about how Madara hated anyone being behind him like when he's peeing and Hashi stands behind him
Also in that link there's a mistake and it says Senji instead of Senju which I thought was funny
Sorry if something along these same lines has already been posted
Further Edit: http://naruto.wikia.com/wiki/Izanagi
~Naruto&Itachi~ showed me that you actually don't need Senju cells to do Izanagi, they just make it last longer.
Having said this, I still believe 100% that Madara didn't use Izanagi because he gave both his eyes to Nagato