Urine nitrite

Some bacteria in the urinary system can reduce the nitrate of protein metabolites in the urine to nitrite, so the determination of the presence of nitrite in urine can quickly and indirectly know the urinary bacterial infection. Screening test. The incidence of urinary tract infections is high clinically and sometimes asymptomatic, especially in female patients. The diagnosis of urinary tract infection requires urinary bacterial culture, which requires a long time and certain conditions, and the qualitative experiment of urinary nitrite can quickly obtain results, which is helpful for the auxiliary diagnosis of the disease. When people with obvious urinary tract infections use bacteria to reduce nitrate to nitrite, phenol coupling produces red as a positive reaction. The positive rate of urine nitrite depends on the retention time of urine in the bladder for more than 4 hours, and the positive rate can reach 80%. Negative results can also occur if urinary tract infection bacteria cannot reduce nitrate to nitrite, or if urine stays in the bladder for a short time, or lacks nitrite in urine. A positive result indicates that the number of bacteria in the urine is more than 100,000 / ml.