Gene expression report format Textual format Experiment annotation format ISA-TAB 1.13 The Investigation / Study / Assay (ISA) tab-delimited (TAB) format incorporates metadata from experiments employing a combination of technologies. ISA-TAB is based on MAGE-TAB. Other than tabular, the ISA model can also be represented in RDF, and in JSON (compliable with a set of defined JSON Schemata).