Analytical performance of the Iris iQ200 automated urine microscopy analyzer

Abstract

Background We evaluated the Iris iQ200 Automated Urine Microscopy Analyzer to find out if the instrument performed better than traditional visual bright field microscopy in detecting basic urine particles, as assessed against reference phase contrast microscopy. Methods The HUSLAB quality system was followed in planning and completing the evaluation process. The iQ200 instrument results from 167 mid-stream, uncentrifuged urine specimens were compared to those obtained with phase contrast reference microscopy, and to those with routine bright field microscopy. Linearity, carry-over and precision were tested according to well-established protocols. Results The iQ200 counted erythrocytes (RBC) at r = 0.894 ( R 2 = 0.799) with Automated Particle Recognition (APR) software alone and at r = 0.948 ( R 2 = 0.898) after re-classification. The performance for leukocytes (WBC) was r = 0.885 with APR and r = 0.978 after re-classification. The correlations of counting after user re-classification were r = 0.927 for squamous epithelial cells (SQEP), r = 0.856 for casts, and r = 0.706 for non-squamous epithelial cells. The iQ200 showed good linearity and precision and no carry-over was detected. Conclusions The Iris iQ200 was capable to count reliably RBC, WBC, and SQEP cells and to identify a fraction of bacteria and renal elements. Counting results equalled or exceeded that of routine bright field microscopy or earlier flow cytometric technology. The instrument eliminates manual sample preparation but requires a well-trained technologist for re-grouping of findings.