Twinsensor BT :( Rapid Test for B-lactom + Tetracycline residues in Milk)

Introduction :
Twinsensor BT is a receptor-based assay in a dipstick format for rapid detection of B-lactam and tetracycline molecules present in a milk sample.
Incubation time in this kit is 6 minutes in temperature of 50± 3 °c, and it is available in two models: 25 test & 96 test.
Reaction mechanism :
Twinsensor BT is a competitive test involving two receptors in one single operation. The test requires the use of two elements. The first element is a microwell containing a certain amount of both receptors and antibodies linked to gold particles and the second is a dipstick made up of a set of membranes where there are capturen lines. The “control” line printed in red is visible all the time and the two others are the spesific “test” lines placed on both sides of the control line. The unique line for penicillins and cephalosporins is located below the “control” while the line relating to tetracyclines is located upper.
When reagent from the microwell is re-suspended with milk sample, both receptors could bind the corresponding analytes over the first incubation that takes place at 50ºC for 3 minutes. Afterwards, when the dipstick added into the milk, the liquid start running vertically on the dipstick and passes throughout capture’s zones. When the sample is free of antibiotic, coloure development occurs at specific capture lines indicating the absence of the concerned analytes into the milk sample. On the opposite, the presence of antibiotic in the sample will not cause the appearance of the coloured signal at specific capture lines.
Detection limits :

B-lactams:	Ampicilin 3 – 5  ppb Amoxicillin 3 - 5   ppb Benzylpenecillin 2 - 3   ppb Cefazolin 20-25  ppb Cefoperazone 2 - 3    ppb Ceftiofur 10 –15 ppb Cephapirin 4 - 8    ppb Cloxacillin 4 - 8    ppb Nafcillin 40 - 50 ppb
Tetracyclines:	Chlortetracycline 25 - 30 ppb  Doxcycline 10 -20  ppb  Oxytetracycline 30 - 40 ppb  Tetracycline 40 - 50 ppb