In general, proteinuria is defined as greater than 110 mg/m2 and 85 mg/m2 per day for infants (under one year of age) and children (over one year of age to ten years old), respectively, and greater than 145 mg/m2 for newborns (under 30 days of age). Children suspected of having proteinuria on an outpatient basis usually need to be hospitalized to complete a series of tests to confirm the diagnosis of the disease, exclude secondary causes, and complete preparations for treatment with medications. Most children with nephrotic syndrome do not require a kidney puncture. A test paper analysis is also required, which is the most commonly used method to determine the amount of urine protein. In the absence of urine protein, a yellow color is seen, and the protein in the urine interferes with the binding of the dye to the retardant. The protein in the urine interferes with the binding of the dye to the retardant, causing the yellow color to change to green. Morning urine is preferred, as it is the most concentrated and can rule out postural proteinuria. Qualitative tests are screening tests only and are not used as an accurate indicator of urine protein levels.