A Vickers M300 analyser has been successfully installed in a busy hospital laboratory. A permanent team of operators is used, but this introduces problems for staff rotation, particularly for educational purposes. The vials used for the collection of samples are an essential feature of the system, but they present many difficulties and are no longer used for collecting samples from outpatients, or at remote sites. Direct costs during 1974, excluding staff and depreciation, amounted to approximately pounds 0-45 per patient sample: this is assessed on the rising workload during implementation. An increased workload could still be handled with existing staff. The siting of such high-capacity analysers constitutes an important policy decision.