High-throughput pretreatment system in automated urinary sediment analyzer

Background: Urine contains microscopically observable particles that can in dicate certain types of disease in the urinary tract system. Determining th ese various types of sediments by manual operation is a cumbersome and time -consuming task. To eliminate this labor, we developed an automated urinary sediment analyzer with high-throughput pretreatment system. Methods: The pretreatment system mainly consists of four reaction vessels f or dying samples (urine), a sheath flow chamber, and an unique sample carri er mechanism from the reaction vessel to the flow chamber, which enables ov erlapped processing, and rapid transfer of samples with small dispersion an d a short buildup time. Results: The buildup time was experimentally found to be 1.8 s, and the ext ra-sample volume beside that for measurement was only 4.9 mu l (1/20 of the total sample volume). Conclusions: Short buildup time results in high throughput of 120 samples p er hour, and relatively small extra-volume contributes to reduce carryover. (C) 2000 Wiley-Liss, Inc.