The problems of using sterile supplies and re-using them, with considerable capital expenditure and large numbers of staff, prompted a concern with new products that would avoid all the burdens of conventional products. The eighth edition, published in 1977, lists 183 firms but the number of product groups cannot readily be compared in view of the increase in their variety but probably something like 200 distinctive groups are listed. The field covered by the service is continually growing in response to enquiries, particularly from people working in the Clinical Research Centre. Information on bio-medical instrumentation, and the materials and components for constructing these instruments, is essential to the work of the Bio-engineering Division. The suppliers index lists the names and addresses of all the manufacturers and suppliers in the system, using ‘visible indexing’ cards filed in alphabetical order of company names. White cards are used for UK companies.