To Determine the Quantity of Proteins in Urine Sample Using Biuret Reaction
Healthy persons excrete urine that is largely free of proteins. The analysis of urine for the presence of proteins is important for the diagnosis of renal, cardiac, and thyroid-related diseases. Several physiological and pathophysiological mechanisms cause the urinary excretion of proteins. The normal protein excretion in urine is about 30–150 mg/day. About one third of the total urinary protein is albumin, and the remaining includes many small globulins. The presence of excess proteins in urine often causes the urine to become foamy, but other conditions like presence of bilirubin in the urine (bilirubinuria), pneumaturia (air bubbles in the urine), or drugs may also make urine foamy. The presence of increased amounts of proteins in the urine may indicate a serious disease problem or may appear before any other clinical symptoms.