Evaluation of the clinical chemistry analyser Olympus AU400.

The Olympus AU400 analyser (Olympus, Tokyo, Japan) is an automated chemistry instrument for turbidimetric, spectrophotometric and ion selective electrode measurements. Overall analytical performances of the AU400 and the reagents provided by Olympus were evaluated according to the French Society of Clinical Biology guidelines. Twenty parameters including specific proteins, substrates, enzyme activities and electrolytes were tested. The linearity exceeded the specifications given by the manufacturer. Within- and between-run imprecision (CV%), evaluated at two levels, was below 1.5% for ion selective electrode parameters and 3% for other analytes, except for CO2, alkaline phosphatase at low levels and magnesium. Results compared well with those obtained with the analysers routinely used in our laboratory (Behring BNII, Olympus AU800 and Beckman CX3 Delta). The usual positive interferences from lipaemia and haemoglobin on total protein measurement were observed. Creatine kinase and alkaline phosphatase assays were the subject of positive and negative interference by haemoglobin, respectively. There was a negative interference by bilirubin in the uric acid, aspartate-amino transferase, creatine kinase and lactate dehydrogenase assays and a positive interference in the calcium assay. The system was found to be very easy to use and the workstation is user-friendly.