A material which is used to verify the performance of an assay intended to be used for the qualitative and/or quantitative detection of multiple antigens or markers associated with acute kidney injury (AKI) in a clinical specimen. The range of analytes detected may include (but is not limited to) insulin-like growth factor-binding protein 7 (IGFBP-7), neutrophil gelatinase-associated lipocalin (NGAL), tissue-inhibitor of metalloproteinase-2 (TIMP-2), cystatin C, kidney injury molecule-1 (Kim-1) and/or L-type fatty acid–binding protein (L-FABP).