Anatoxin-a (VFDF), 0-2.5 ppb, Dipstick, Source Drinking Water, 20 tests
The Anatoxin-a Strip Test for Water is a rapid immunochromatographic test, designed solely for use in the qualitative screening of Anatoxin-a in fresh water. The Anatoxin-a Strip Test provides only preliminary qualitative test results. If necessary, positive samples can be confirmed by ELISA, HPLC or other conventional methods. The test is based on the recognition of Anatoxin-a by specific antibodies. The toxin conjugate competes for antibody binding sites with Anatoxin-a that may be present in the water sample. The test device consists of a vial containing specific antibodies for Anatoxin-a labeled with a gold colloid and a membrane strip to which a conjugate of the toxin is attached. A control line, produced by a different antibody/antigen reaction, is also present on the membrane strip. The control line is not influenced by the presence or absence of Anatoxin-a in the water sample and, therefore, should be present in all reactions. In the absence of toxin in the water sample, the colloidal gold labeled antibody complex moves with the water sample by capillary action to contact the immobilized Anatoxin-a conjugate. An antibody-antigen reaction occurs forming a visible line in the ‘test’ area. The formation of two visible lines of similar intensity indicates a negative test result, meaning the test did not detect the toxin at or above the cut-off point established for the toxin. If Anatoxin-a is present in the water sample, it competes with the immobilized toxin conjugate in the test area for the antibody binding sites on the colloidal gold labeled complex. If a sufficient amount of toxin is present, it will fill all of the available binding sites, thus preventing attachment of the labeled antibody to the toxin conjugate, therefore preventing the development of a colored line. If a colored line is not visible in the test line region, or if the test line is lighter than the control line, Anatoxin-a is present at a level of concern. Semi-quantitative results can be obtained by comparing the sample test strip appearance to the appearance of test strips from solutions of known Anatoxin-a concentrations (control solutions). Concentrated Anatoxin-a standards which can be used to prepare Anatoxin-a controls are available through Eurofins Abraxis (PN 300620).
|Test principle||Immunochromatographic assay on strip|
|No. of tests||20|