Rack for a filtration device

A method of filtering a liquid, the method comprising the steps of:

• (a) obtaining a filtration device, comprising:
• at least one container;
• a rack for a diagnostic robot, the rack comprising at least one support for the at least one container to firmly hold the at least one container in a pre-determined position of the rack, at least one gas-outlet to supply the at least one container with a gas at a pre-defined but individually adjustable pressure level, a first gas pump to generate a pre-defined super-atmospheric pressure level of the gas, a second gas pump to generate a pre-defined sub-atmospheric pressure level of the gas, a first tubing system attached to the first gas pump and holding the gas generated by the first gas pump, a second tubing system attached to the second gas pump and holding the gas generated by the second gas pump, at least one tube bridge having one that connects via a first valve into the first tubing system and another end that connects via a second valve into the second tubing system, and wherein the at least one gas-outlet is connected to the center of the bridge;
• a lid covering the at least one container, wherein the lid exhibits an opening, wherein the lid holds an object carrier which includes a filtration assembly comprising a filtration membrane and a supporting body;
• and
• an adapter on the at least one container or lid, wherein the adapter is attached to the at least one gas-outlet on the rack so that a gas leak proof connection is established between the at least one container or lid and the rack;
• (b) applying a liquid to be filtered onto the filtration assembly of the filtration device;
• and
• (c) opening the second valve until the pre-determined sub-atmospheric gas pressure has been generated in the at least one container, resulting in filtration of the liquid.