Under Australian law it is possible to make post grant amendments to a patent either before the Commissioner of Patents, or in the Federal Court of Australia. Typically an application for amendment to the Federal Court is lodged when the patentee is about to commence infringement proceedings on the basis of advice that amendments are required to correct defects or to limit the relevance of prior art. In a recent case, Gambro Pty Ltd v Fresenius Medical Care South East Asia Pty Ltd, amendments were sought to limit the field of invention to the area of real interest fluids for dialysis and related procedures in order to strengthen the patentee´ s position in a cross claim for invalidity.