Depending on the usage/category of Biomaterials, like surface biomaterials, implants, they must undergo different types of testing which are set by ISO 10993 standards like cytotoxicity, genotoxicity, sensitization, chronic toxicity, carcinogenecity. For example, a surface biomaterial should be tested for its interaction with body tissues and also with external environment as specified by ISO standards. For an implant which stays in contact with body tissues forever it should be tested for its interaction with body tissues (biocompatibility) as set by ISO standards. Once the biomaterial is tested for all tests depending on the category, it can be used for clinical trials after getting approval.