Comparative evaluation of automated systems in immunohistochemistry

From October 1995 to March 1997, we evaluated five instruments for immunohi stochemistry automation: The Techmate 500 (Dako), the Ventana 320/ES (Venta na), the Optimax Plus (Biogenex, Menarini), the Cadenza (Shandon), and the Immunostainer (Coulter-Immunotech). The aim of the evaluation was to compar e the different instruments to the manual method in our laboratory which pe rforms about 17 500 immunohistochemistries per year. Principle: Three instr uments use flat immunohistolabelling, the others use capillarity immunohist olabelling. Analytical flexibility: we compared the number of protocols per run, the multitask capability, and the ability to adapt manual protocols t o the different instruments. To compare the management of the workcell, we used the level of selfchecking, reagent and slides preparation time, and wa ste management. We measured the duration of the different steps of the proc ess, the throughput in slides/h, and the operator working time per slide. C ompared to the manual method, the total cost for reagents and consumables w as found to be multiplied by 3 for the Ventana which is a closed system, by 2 for the Techmate, by 1.5 for the Optimax and Cadenza, and identical for the Immunostainer. Conclusion: Automation of immunohistochemistry is now po ssible; the Optimax is still in development, small laboratories will apprec iate the Cadenza, laboratories requiring a high flexibility with many proto cols will use thr Immunostainer open system, laboratories with few technici ans will prefer the Ventana closed instrument, now available as the Nexes m odular system. (C) 1998 Elsevier Science B.V. All rights reserved.