The strains were developed to be used in conjunction with our SIMUL-qPCR with GFP Assays to help detect laboratory cross-contamination. These positive control strains are tagged with a green fluorescent protein (GFP) that is not naturally found on the pathogen of interest. The assays are able to detect the target pathogen and GFP, immediately signaling laboratory contamination if found in a sample other than the positive control.