The design translates the biological perturbation into a detectable signal, leading to one or more measurable outcomes (endpoints) that quantify or qualify the effect. Key components of a bioassay include the assay format, biological participants, design method, screened entity, and endpoints. The bioassay is represented by bao:BAO 0000015 class from the bioassay ontology (BAO) . This class is the highest level class for bioassays and it has many subclasses representing more specific types that can be assigned to the bioassay depending on its type. For example, class bao:BAO 2785 for gene expression assays, class bao:BAO 0002761 for cell viability assays, and class bao:BAO 0010009 for physicochemical assays. The bioassay has a specification that describes the assay, for example, endpoint assay (bao:BAO 0000410 ) where the result is a static response such as cell viability. Moreover, it has a protocol (bao:BAO 0000523 ) that includes the methodology used to perform the assay, and an assay format (bao:BAO 0000019 ) that is based on the biological/chemical features of the bioassay such as organism-based format (bao:BAO 0000218 ) or cell-based format (bao:BAO 0000219 ). For a cell-based format, it is further described by having a cell line (bao:BAO 0000001 ) that is in turn derived from both an organism (bao:BAO 0000551 ) and an anatomical structure or a biological system (ncit:ncit:NCIT C12219 ). Furthermore, a bioassay has one or more measure groups bao:BAO 0000040. A measure group is used to group and link multiple (different) sets of experimental results to one bioassay. It links to a target and a participant where both are represented by a molecular entity class bao:BAO 0003043. The target can be a gene, protein, or another entity targeted by the perturbing agent. The participant is the perturbing agent, for example, a chemical compound or a nanomaterial which has a perturbagen bao:BAO 0003059 and a screened entity bao:BAO 0002932 roles. The measure group also links to one or more endpoints. The endpoint is a standardized, interpretable measure -either quantitative or qualitative-that represents a change from a defined reference state in a "closed" model system, as detected by the bioassay. The endpoint class has different subclasses, among which is the response endpoint class bao:BAO 0000181, which reports the magnitude of the perturbation such as percent inhibition. The endpoints have a unit represented by any suitable ontology class, a value with a literal type and links to a screening concentration endpoint class bao:BAO 0000098, which in turn has a unit and value. Moreover, if the measurements are taken at specific time points, the endpoint can have a time unit and a time value linked to it.