TwinSensor Plus is a competitive test involving specific receptors and monoclonal antibodies in one single operation. The test can be used in-situ for daily controls or in laboratories for the analysis of series of milk samples. This test does not require any sample processing, cleaning or extraction. TwinSensor Plus (KIT106) is as fast as Unisensor’s classic TwinSensor (KIT020). And now, it detects Cefalexin too!
The test requires the use of two components:
The first component is a microwell containing predetermined amounts of both receptors and antibodies linked to gold particles.
The second is a dipstick made up of a set of membranes with specific capture lines.
For a valid test, the top control line has to be present. When the reagent from the microwell is re-suspended with a cow milk sample, both receptors and monoclonal antibodies will bind the corresponding analytes if present during the first 3 minutes incubation at 40°C. Afterwards, when the dipstick is dipped into the cow milk, the liquid starts running vertically on the dipstick and passes through capture zones.
If the sample is free of antibiotics, a color development occurs at the ‘test’ lines, indicating the absence of the targeted analytes in the cow milk sample. On the contrary, the presence of antibiotic(s) in the sample will impair the reagent to color the ‘test’ line. In any case, the top ‘control’ line must be colored to validate a test. If it is not, consider the analysis as invalid and do not start (or continue) any interpretation.
Beta-lactams and Tetracyclines antibiotics are the most widely used antibiotics for the treatment of bacterial infections in dairy cattle. A specific indication for administrating both antibiotic types is infectious mastitis. These drugs are also administered to animals in feed for growth promotion and for collective prophylactic treatment.
The monitoring of Beta-lactams and Tetracyclines in milk is important because of the hypersensitivity of some individuals to these antibiotics and also because of the emergence of antibiotic-resistant strains of bacteria. In addition, the general residual level of antibiotics could alter the efficiency of industrial processing of raw milk toward cheese or other fermented dairy products preparation.