These records have been separated by their originating bodies (for example, ABRO or Roslin) and arranged by function (for example 'Governance' or 'Legal'). As well as the records of the Institute Secretary, which make up the majority of the collection, some series contain records of the director, assistant director and individual scientists as well as the Institute Secretary. These distinctions have been noted on the catalogue.

The material has been ordered into series to accord with certain general functions in the catalogue's arrangement, such as 'Legal Records' and 'Governance' etc. The same functional categories apply within each sub-fonds. However there will be a considerable degree of overlap between the files within the separate series. For example, a researcher interested in a certain research project may find relevant records in 'Legal Records' under 'Contracts' as well as 'Financial Management' under 'Grants and Funding' and so on. Where possible, reference is made within the catalogue to related materials.

Due to the various reorganisations and mergers which make up the somewhat complex back history of Roslin Institute, files have been placed within an individual organisation's catalogue according to the start date of the file. For instance, a file with a large span of dates may contain papers of the PRC, IAPGR and the Roslin Institute - but the file will sit within the PRC. Researchers should be aware to look at the span of dates of each file to ascertain what kind of institutional material it may hold.