The influence of urine specimen storage time on the determination results of RBC and WBC in urine

Objective To investigate the influence of different urine specimen storage time on the count of the cells in urine and the morphology of red blood cell.Methods The automatic urinary sediment analyzer UF-1000i was used to analyze the numbers of red blood cell,white blood cell and epithelial cell in urine immediately and after 1 h,2 h,3 h,4 h and 5 h.The morphology of red blood cell was observed by microscopy simultaneously.Results Compared with the results of fresh urine,the number of red blood cell had an obvious decreasing change after 4 h(P0.05).The numbers of white blood cell and epithelial cell did not show obvious change within 5 h(P0.05).The morphology of microcyte did not alter within 5 h,while the morphology of the macrocyte had the changes of crenulation and abnormal red blood cell increasing after 3 h.Conclusions For ensuring a reliable and accurate results,specially the morphology of red blood cell in urine,the urine specimen should be fresh and be determined within 4 h.