Interaction effects and assay compatibility problems have been specifically demonstrated in
screening bioengineered nanomaterials. Engineered nanomaterials vary in diversity and complexity of
the types of materials and have different physicochemical properties [73]. As a result, it has been
recommended that a diverse portfolio of cell viability and cytotoxicity assays (including the Alamar
Blue assay) with different chemistries and detection mechanisms should be used for the assessment of
nanoparticles or nanomaterials [74,75]. One reason is that some nanoparticles may interact with assay
chemistry [76] and there is difficulty in determining in vitro effects [77]. Further, the composition of
the culture medium and the nanomaterials itself, use of dispersants or other additives, the proliferation
rate and the type of the cells used in the assay may also have an effect on assay outcome [76,78].