Final answer:
The Sulfosalicylic acid turbidity test is used to confirm significant amounts of protein in the urine and evaluate concentrations.
Step-by-step explanation:
The test that is used to confirm significant amounts of protein in the urine and uses the supernatant to evaluate the concentrations is the Sulfosalicylic acid turbidity test. This test works by adding sulfosalicylic acid to the urine sample, which causes any proteins present to precipitate. The amount of turbidity, or cloudiness, that occurs in the sample is then measured to determine the protein concentration.