Arkray Sulphosalicylic Acid 30% is a laboratory reagent used for the semi-quantitative evaluation of proteinuria in urine, up to 500 mg/dL. It works by causing the precipitation of dissolved proteins in the urine, which can then be measured based on the resulting turbidity. The solution is typically supplied in a 500ml bottle, has a purity of 99%, and a shelf life of 36 months.