Is it permissible for usurious money to be commingled with non-usurious money, especially in the Islamic bank branch that is affiliated with a usurious bank?

The mere mixing of funds from an Islamic branch and its usurious origin does not affect it, because the prohibition is not related to the money itself, but rather to the extent of the Islamic branch's adherence to Sharia regulations in its transactions and its immunity from the influence of its usurious origin.