The gold standard for the diagnosis of Wilson disease is:
The gold standard for diagnosis is liver biopsy with quantitative copper assays. Affected patients have values > 200 mg/g dry weight of liver tissue. Copper stains are not reliable. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 3188
Liver biopsy with quantitative copper assay
Serum ceruloplasmin along with free copper estimation
24 hour urine copper quantification
Liver biopsy and copper staining