Principle

The FSTest Heavy Metal Pb Rapid Test Strip is based on immunochromatographic assay. The test strip has an area for result reading, which has a T (Test) line and C (Control) line. Both lines are invisible before testing. When the sample is applied to the loading side of the strip, the liquid will laterally flow upward through the surface of the test strip and react with the pre-coated recombinant antigens. If there is amount of heavy metal lead (Pb) in the sample, the intensity of T line will be inhibited and become relatively lighter than C line. Meanwhile the C line should always appear after a sample is applied, which indicates a valid result. By this means, the device can indicate the presence of heavy metal lead (Pb) in the sample.

Limit of detection

Milk and milk products: 0.2 mg/kg

Raw milk, pasteurized milk, and

sterilized milk: 0.02 mg/kg

Prepared milk and fermented milk: 0.04 mg/kg

Drinking water: 0.005 mg/L 

Kit composition

Test strips ×10

Microwells ×10

Heavy metal Pb reagent A ×1

Heavy metal Pb reagent B ×1

Heavy metal Pb chelating agent ×1

Heavy metal Pb diluent solution ×1

1.5 mL Centrifuge tubes x 20

User manual

Procedure & Steps

1. Pipette 50 μL of sample into a 1.5 mL centrifuge tube.  

2. Add 350 μL of heavy metal Pb reagent A and 10 μL of heavy metal Pb chelating agent into the tube, re-cap the tube tightly, vortex for 10 s to mix.

3. Add 100 μL of heavy metal Pb reagent B and 100 μL of heavy metal Pb diluent solutions into the tube, re-cap the tube tightly, vortex for 10 s to mix.

4. According to different sample types to perform the following steps.

For drinking water, raw milk, pasteurized milk, and sterilized milk, the samples from step 6.3 are ready for the test.

For prepared milk and fermented milk, pipette 100 μL of mixture from step 6.3 into a 1.5 mL centrifuge tube and add 100 μL of diluent solution, vortex to mix, and then ready for the test.

For milk products, pipette 100 μL of mixture from step 6.3. into a 1.5 mL centrifuge tube and add 900 μL of diluent solution, vortex to mix, and then ready for the test.

5. Pipette 120 μL of sample into the microwells pre-coated with reagent, mix slowly but thoroughly with pipette, then incubate for  3 min at room temperature (20-40℃).

6. Insert the test strips into the microwells and start timing.

7. Interpret the results in 5-8 min. Results are invalid after 10 min.