High-throughput pretreatment system in automated urinary sediment analyzer.

Background: Urine contains microscopically observable particles that can indicate certain types of disease in the urinary tract system. Determining these 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 for dying samples (urine), a sheath flow chamber, and an unique sample carrier mechanism from the reaction vessel to the flow chamber, which enables overlapped processing, and rapid transfer of samples with small dispersion and a short buildup time.

Results: The buildup time was experimentally found to be 1.8 s, and the extra-sample volume beside that for measurement was only 4.9 microl (1/20 of the total sample volume).

Conclusions: Short buildup time results in high throughput of 120 samples per hour, and relatively small extra-volume contributes to reduce carryover.