Little question about monsters and shadows!

Mad science has begun, Rau and Gil are taking an Umbra to the vet - which brings a great question to the forefront of my mind: can you draw blood from a monster? Or does the syringe draw anything else? If it's blood, what is Umbra blood like?

I don't expect any major plot reveals from this silly thread, but this particular bit made me curious enough to actually come ask!