ENVI Assay System Gold employs immunochromatographic lateral flow test format for qualitative detection of the presence of selected BWAs in environmental samples. During the test procedure, an environmental sample (powder, liquid, soil, air, surface sample) is collected with a cotton swab and solubilized in a sample buffer. The gold-labelled antibody reagents of the test, included in the unique filter tip of the buffer vial, bind specifically to the biological agent of interest (an antigen) in the solubilized sample, when mixed together. After dosing a small amount of the mixed solubilized sample on a test cassette, the complex formed by the antigen and the gold‐labelled antibodies migrates along the test membrane by capillary force (lateral flow) and binds to the stationary antibody in the test membrane, forming a visible red test line. The test strip also contains an integrated control system with a red control line showing the proper functioning of the test. Lateral flow immunoassays are handy tools for performing rapid screening of potential biological threat agents either in the field or in laboratories.