A method for high fluid shear processing of a fluid uses an isolator that has a first sub-chamber for containing a first fluid and a second sub-chamber for containing a second fluid defined by a separator positioned in the chamber and movable between a first end of the chamber and a second end of the chamber. The two sub-chambers are in pressure communication with each other but are not in fluid communication with each other. A first fluid is pumped at an ultrahigh pressure into the first-sub chamber, and the pressure in the first sub-chamber causes a second fluid to be processed to be discharged from the second sub-chamber into a processing valve. A system is also provided for performing the steps of this method.