[An instrument for measuring the protein concentration in urine]

The measuring of the protein concentration in urine provides for an early diagnosis of a number of diseases at the early stage of their onset. Determination of the protein concentration in urine in patients after renal transplantation made during the early postoperative period is of special diagnostic importance. The protein content in urine varies significantly during 24 hours. With urgent information on losses of the protein in urine being available, the doctor can correct, purpose-orientedly, such losses, assess the activity of the pathological process in the kidneys and evaluate the efficiency of a conducted treatment. The known methods of determining the protein concentration in biological liquids are discussed; their advantages and disadvantages are pointed out. We suggested a new method for determining the protein content in urine, which is based on changes in the electric resistance of fluid (urine) according to its protein content; the method was patented in Russia. The technique of measuring the protein concentration in urine consists in measuring the electric resistance of the examined urine before and after its filtration through a micro-pore filter, with a pore size of 2-3 nm (2-3 x 10(-9) m), intercepting the protein. There is a description of the elaborated-by-authors instrument, which is based on the mentioned technology and which cuts the time of determining the protein concentration in urine; it also makes any chemical reagents unnecessary and provides for automating the measurement process.