A material which is used to establish known points of reference for as assay intended to be used for the quantitative and/or qualitative detection of nucleic acid from multiple microorganisms associated with gastrointestinal disease, in a clinical specimen. Microorganisms detected may include bacteria, viruses, fungi and/or parasites such as, but are not limited to Salmonella, Shigella, Campylobacter, Escherichia coli (E. coli), Norovirus, Rotavirus, Clostridium difficile, Giardia, Bacillus and/or Vibrio species.