4Sensor BSTQ - KIT072

Rapid Test Detecting Simultaneously Betalactams, Sulfonamides, Tetracyclines, And (Fluoro)quinolones In Milk


4Sensor is a rapid assay in dipstick format detecting the contamination of milk samples by Betalactams, Sulfon- amides, Tetracyclines, and (Fluoro)quinolones molecules


4Sensor BSTQ is a competitive test involving specific receptors and generic monoclonal antibodies in one single operation.

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.

4Sensor BSTQ

For a valid test, the upper red control line has to be visible after the second incubation. The other 4 lines are the specific “test” lines placed below the control line.

When the reagent from the microwell is re-suspended with a milk sample, both receptors and monoclonal antibodies will bind the corresponding analytes if present during the first 5-minute incubation at 40°C. Afterwards, when the dipstick is dipped into the milk, the liquid starts running vertically on the dipstick and passes through capture zones. This is the 5 minutes migration step.

When the sample is free of antibiotics, a colour development occurs at the specific capture lines, indicating the absence of the targeted analytes in the milk sample. On the contrary, the presence of antibiotics in the sample will not cause the coloured signal to appear at the specific capture lines.


  • Simultaneous Detection Of Residues
    Multiple 4x Simultaneous Detection Of Residues
  • Rapid
  • Adapted To Specific Regulations
    Sensitive Adapted To Specific Regulations
  • Easily Performed On Site Or In The Lab
    User-Friendly Easily Performed On Site Or In The Lab
  • Reliable And Robust
  • Cost-Effective

Good to know

The detection of residual antibiotics such as Betalactams, Sulfonamides, Tetracyclines, And (Fluoro)quinolones in milk is of great concern for the dairy industry because of the potential interfering and adverse effects of antibiotic residues frequently found in milk.

Unisensor has developed a multiplex dipstick assay for the rapid and simultaneous detection of these antibiotics. This unique test does not require any sample preparation and gives a clear result by visual observation or using an instrumental reader in only 10 minutes. The presence of each antibiotic family can be discriminated thanks to the use of 4 separate test lines.

How to use

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.

  1. Add 200 μl of milk into one reagent microwell and mix to homogeneity;
  2. Incubate 5 min at 40°C;
  3. Dip one Dipstick into each microwell;
  4. Continue incubating for 5 min at 40°C;
  5. Read the colour intensities.

An instrumental reading is also possible with the ReadSensor device.

Technical Details

Catalogue Reference : 4Sensor BSTQ MILK MRL - 96 PC