"isolated from the rest" is a correct expression and can be used in written English.
For example: "The small island was isolated from the rest of the continent by a wide ocean."
This discontent, too, is isolated from the rest of society.
The city is isolated from the rest of Australia.
They had also been isolated from the rest of Iraq, as punishment for challenging Saddam's rule.
Texas's power grid, for example, is already largely isolated from the rest of the country's.
Israel and America are becoming further isolated from the rest of the world.
In February Rowsell spent a period isolated from the rest of the squad.
Myanmar can no longer remain isolated from the rest of the world.
Texas is mostly isolated from the rest of North America, in electricity terms.
In the first few weeks of TU, they're highly isolated from the rest of the company.
Like other northeastern states, it is largely isolated from the rest of India.
MILLIONS OF EDUCATED and prosperous Iranians resent being isolated from the rest of the world.
