The present application relates to a multizone, unsupported, microporous, high throughput membrane. The membrane includes a first microporous zone, a second microporous zone, and a third microporous zone, where the third microporous zone is positioned between the first and second microporous zones, with the first, second, and third microporous zones being integral with one another. Further aspects of the present application include a process for making the membrane and a filtration cartridge with the membrane of the present application.