An evaluation of the Monarch chemistry analyser

The Monarch Chemistry system, a centrifugal analyser incorporating sophisticated robotics for analytical rotor transfer and flexible software for workload scheduling, has been evaluated. The optical system is capable of monitoring absorbance, fluorescence and light scattering reactions. In addition, an ion selective electrode unit may be incorporated for the measurement of sodium, potassium and chloride.The precision, accuracy, linearity, calibration stability and carry-over were investigated for 19 routine chemistries. The within-batch and between-day precision data were good in the majority of cases; some chemistries demonstrated poor performance at low analyte concentrations. Method comparison studies showed good agreement, with small discrepancies being due to different calibration material and methodological differences. Major discrepancies were found with CK and LD; linearity studies were good in all cases, except calcium. No significant sample or reagent carry-over was found.Assessment of throughput for a variety of test profiles varied between 300 and 605 tests per hour.The instrument was easy to operate, very flexible and capable of handling a large and varied workload.     

First basic performance evaluation of the XE-2100 haematology analyser

The newly developed XE-2100 haematology analyser can provide complete blood counts, leukocyte differentials, perform reticulocyte analysis, and obtain quantitative data on nucleated red blood cells (NRBCs). In this study, we evaluated the basic performance of this instrument using routinely obtained blood specimens treated with ethylenediaminetetraacetic acid-2k. Reproducibility, carryover, stability during storage at 4 degrees C and room temperature, and accuracy were evaluated. In this evaluation, reproducibility was good and little carryover was found. Accurate measurements were possible for up to 48h of storage. A good correlation between findings with the XE-2100 and SE-9000 haematology analysers was found for complete blood count on 210 samples tested. The leukocyte differential obtained with the XE-2100 correlated well with eye counts and with the results obtained with the SE-9000 automated haematology analyser, with r values over 0.9 for the percentages of neutrophils, lymphocytes and eosinophils. The precision and accuracy of VRBC and reticulocyte counts by the XE-2100 were satisfactory. We used the XE-2100 to obtain differential counts for bone marrow aspirates, and good correlations with manual differentials were obtained for total nucleated cell count, percentage of myeloid cells and percentage of erythroid cells. The performance of the XE-2100 was excellent, and this instrument should be able to provide reliable data to clinical laboratories.     

Laboratory evaluation of the COBAS MIRA S random access analyser

The random access analyser COBAS MIRA S (Roche Diagnostics) was evaluated for two months. The instrument is a computer-controlled discrete analyser which can be run in a combination profile and single test mode. This instrument has special features, including an automatic cuvette segment changer, a reagent rack cooling system, an external keyboard and monitor, as well as a bar-code facility for the entry of test parameters, worklists and sample identification numbers. Study of within-run and between-run precision gave values of % CV 0.54-3.37 and 0.61-3.65, respectively, for a variety of assays. Linearity testing to the upper limit of each test was also studied and were found to cover the necessary pathological range. Within the two-month period, no major problems were encountered. The instrument required minimum operator attention during operation. Correlation studies with the Hitachi 705 using six clinical chemistry tests (glucose, cholesterol, triglyceride, ALP, AST, ALT) gave correlation coefficients ranging from 0.95-0.99 and slopes of 0.91-1.17.