[Urea (H-N) concentrations in serum and urine including determination variants].

After a concise interpretation of the urea and creatinine values a new variant of the determination of the urea concentration in the serum, the plasma, the urine and other body fluids is described. The determination is done by means of Berthelot's reaction, requires 50 microliters serum and comprehends the concentration range of 0.1 to 100 mmol/l (0.6 to 600 mg urea/100 ml). The method has a good precision, is inexpensive and renders the determination of urea possible in less than one hour.