laboratory diagnostic - testing and comparison - biological samples and assessment reports - quality control - internal - reference strains - qualitative - Escherichia coli O157 non-toxigenic, equivalent collections 700728, NCTC 12900, WDCM 00014, vial x10 discs, keep at freezer, C.F.U between 10^6-10^9, freeze-dried, water-soluble, used in solid or liquid media, code L37RS1023-10, todylaboratories®