Using multiple ASP Identity within MVC5

I've added admin area to an existing MVC5 project for managing content.

The site is currently secured by custom ASP Identity Framework. Now I need to authenticate some user to access the admin area, the user data is in different database with different structure.

It is easy to do this with Membership providers, for example :http://stackoverflow.com/questions/5342158/using-multiple-membership-providers-within-asp-net-mvc-3-application

But is this possible in ASP Identity? I've tried looking everywhere but still nothing.