The FSTest Chlorpyrifos Rapid Test Kit (Colloidal Gold) works on the sandwich lateral flow immunochromatography principle. Its test cassette has a testing window—with invisible T (test) and C (control) zones before use—for monitoring the assay and reading results.

When treated sample is added to the sample well, the liquid flows laterally across the strip and reacts with pre-coated recombinant antigens. The T line’s color intensity is inversely related to the sample’s chlorpyrifos concentration. The C line always appears to confirm a valid test; by comparing T and C line intensity, the kit indicates if chlorpyrifos is present in the sample.

Core Strengths: Accuracy & Reliability at Its Core

Precision-Driven Design: Engineered for targeted chlorpyrifos residue detection, with strict adherence to standardized operational protocols (e.g., specific sample pretreatment and loading steps) that minimize error—ensuring consistent, trustworthy results for every test.

Controlled Performance Conditions: The test cassette must be placed on a flat surface before use, a critical step that maintains detection accuracy by eliminating environmental interference from uneven placement.

Valid Result Guarantees: Results are clearly interpretable within 8-10 minutes, and any readings after 10 minutes are deemed invalid—this strict timing ensures only accurate, non-degraded results are used for decision-making.

Standardized Sample Handling: The kit provides clear guidance for sample pretreatment and dilution (e.g., pipetting specific volumes of supernatant and extracting solution), which preserves kit performance stability during testing processes.

Streamlined Operation for Error-Free Testing

Designed to reduce operational mistakes, the kit follows a clear, step-by-step process:

Sample Pretreatment: Use the recommended extracting solution—take 100 μL of sample, add extracting solution, vortex or shake for 1 minute and stand for 1 minute; if the supernatant is not clear, take 1mL of liquid and centrifuge at 4000 rpm for 3 minutes (clarification ensures no sample impurities affect test accuracy).

Sample Dilution & Loading: Pipette X μL of supernatant into a 2mL centrifuge tube, add Y μL of extracting solution, vortex to mix for 30 seconds; then pipette 100 μL of the prepared sample solution into a microwell, mix 3-5 times with a pipette, stand for 3 minutes, and finally transfer all liquid into the cassette’s sample well to ensure proper reaction.

Result Reading: Interpret results by observing the test cassette, with validity limited to 8-10 minutes—removing ambiguity and ensuring correct result assessment.

Key Considerations for Sustained Reliability

Standardized Operational Steps: Strictly follow the kit’s specified sample volume requirements (e.g., 100 μL for sample loading) and mixing time (e.g., 30 seconds of vortex mixing for dilution) to avoid operational deviations that compromise test accuracy.

Operational Environment: Ensure the test cassette is placed on a flat surface during use, and maintain a clean operational environment to prevent factors that could affect test accuracy.

Sample Clarity Assurance: If the sample supernatant is not clear after standing, perform centrifugation at 4000 rpm for 3 minutes as required to avoid sample impurities interfering with test results.