This part of ISO 10993 specifies requirements and gives guidance on the procedures to be followed in the preparation of samples and the selection of reference materials for medical device testing in biological systems in accordance with one or more parts of ISO 10993. Specifically, this part of ISO 10993 addresses the following: — test sample selection; — selection of representative portions from a device; — test sample preparation; — experimental controls; — selection of, and requirements, for reference materials; — preparation of extracts. This part of ISO 10993 is not applicable to live cells, but can be relevant to the material or device components of combination products containing live cells.