Comparative evaluation of automated systems in immunohistochemistry

From October 1995 to March 1997, we evaluated five instruments for immunohistochemistry automation: The Techmate 500 (Dako), the Ventana 320/ES (Ventana), the Optimax Plus (Biogenex, Menarini), the Cadenza (Shandon), and the Immunostainer (Coulter-Immunotech). The aim of the evaluation was to compare the different instruments to the manual method in our laboratory which performs about 17 500 immunohistochemistries per year. Principle: Three instruments use flat immunohistolabelling, the others use capillarity immunohistolabelling. Analytical flexibility: we compared the number of protocols per run, the multitask capability, and the ability to adapt manual protocols to the different instruments. To compare the management of the workcell, we used the level of selfchecking, reagent and slides preparation time, and waste management. We measured the duration of the different steps of the process, the throughput in slides/h, and the operator working time per slide. Compared to the manual method, the total cost for reagents and consumables was 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 possible; the Optimax is still in development, small laboratories will appreciate the Cadenza, laboratories requiring a high flexibility with many protocols will use thr Immunostainer open system, laboratories with few technicians will prefer the Ventana closed instrument, now available as the Nexes modular system. (C) 1998 Elsevier Science B.V. All rights reserved.