BetaStar® S for Sulfonamides

The milk is wicked through a reagent zone, which contains antibodies conjugated to colloidal gold particles. If sulfonamides are present, they will be captured by the particle-antibody complex. The drug-antibody-particle complex then is wicked onto a membrane, which contains a sulfonamide drug conjugated to a protein carrier. This line captures any uncomplexed drug antibody, allowing the particles to concentrate and form a visible line. As the level of sulfonamides in the sample increases, free drug molecules will complex with the antibody-gold particles. This allows less antibody-gold to be captured in the test line. Therefore, as the concentration of a drug in the sample increases, the test line density decreases. The membrane also contains a control line where an immune complex present in the reagent zone is captured by an antibody, forming a visible line. The control line will always form regardless of the presence of the drug, ensuring the strip is functioning properly.