With the ongoing internationalization of virtual laboratories, the integration of such infrastructures becomes more important. The meanwhile commonly accepted 'glue' for such legacy systems are serviceoriented architectures, based on standardized and accepted Web service standards. We present our concept of the 'experiment as a service', where the idea of service-based architectures is applied to virtual remote laboratories. In our laboratory middleware, experiments are represented as stateful service implementations. We discuss performance, reliability and security in this approach, and show how our solution - the Distributed Control Lab - is applied in the European VetTrend project.