FSTest Beta-Lactams + Tetracyclines + Sulfonamides

+ Aflatoxin M1 4-in-1 Rapid Test Strip (96 Tests)

Product Overview

The FSTest 4-in-1 Rapid Test Strip is an advanced, industrial-grade multiplex screening tool engineered for the simultaneous, independent detection of four major high-risk chemical contaminant categories in dairy products: Beta-Lactams, Tetracyclines, Sulfonamides, and Aflatoxin M1. Antibiotic residues and dangerous mycotoxins pose severe public health concerns and are subject to stringent, zero-tolerance or exceptionally low Maximum Residue Limits (MRLs) globally. This multi-analyte assay provides an all-in-one compliance auditing solution for dairy farms, raw milk collection stations, pasteurization plants, milk powder manufacturers, and import-export border control laboratories.

By consolidating four distinct biochemical screenings into a single, straightforward assay loop, this kit completely eliminates the immediate necessity for complex multiple extraction protocols or separate ELISA microplate platforms. It compresses essential multi-residue milk verification into a simplified, field-ready ambient workflow.

Product Highlights & Key Benefits

· High-Speed Quad-Multiplex Screening:Map out a comprehensive safety profile spanning four major contaminant groups in a single test sequence, providing clear visual results within just 7 minutes.

· Ultra-High Sensitivity Thresholds:Calibrated to deliver ultra-sensitive qualitative screenings that comfortably meet or surpass rigid regulatory cutoffs: Aflatoxin M1 down to 0.05 µg/kg; Sulfonamides down to 2–4 µg/kg across 17 compounds; Tetracyclines down to 5 µg/kg; Beta-Lactams down to 2–4 µg/kg across 18 target compounds.

· Extensive Dairy Matrix Adaptability:Formulated for multi-matrix sample validation, providing highly reliable results for raw milk, pasteurized liquid milk, and reconstituted milk powder formulations.

· Zero-Ambiguity Visual Layout:The reading zone incorporates four separate invisible Test lines (T1, T2, T3, T4) paired with an integrated internal Control (C) line, allowing straightforward interpretation without cross-line visual interference.

· Heavy-Duty Commercial Specification:Supplied in a bulk 96-test pack containing 96 test strips and 96 dry-reagent precoated microwells, making it perfectly optimized for high-throughput batch auditing.

· Institutional Shelf-Life Flexibility:Offers a full 24-month sealed storage lifespan when kept under proper refrigerated parameters (2–8°C), featuring an advanced ambient tolerance profile that permits room-temperature transport and field deployment for up to 30 days.

Technical Principle: Multiplex Lateral Flow Immunochromatography

The test strip utilizes a competitive lateral flow immunochromatographic assay mechanism. The reaction zone features four invisible independent Test lines (T1: Aflatoxin M1, T2: Sulfonamides, T3: Tetracyclines, T4: Beta-Lactams) along with a terminal Control (C) line.

Dairy Sample Resuspension + Microwell Reagents -> Capillary Lateral Flow -> Competition with Pre-coated Recombinant Antigens -> Faded or Absent T-Line (Residue Detected Response)

When the processed liquid milk sample is applied, the fluid flows laterally upward across the strip via capillary pressure, reacting with specialized pre-coated recombinant antigens. If the target residues are absent or safely below the analytical cutoff, a strong color band binds at the corresponding T line. When a contaminant meets or exceeds the threshold, it competitively inhibits antibody binding, causing that specific T line to become visibly lighter or disappear completely compared to the C line. The Control (C) line must always develop normally to indicate a valid testing run.

Step-by-Step Operating Instructions

Sample Matrix Preparation

Ensure both the dairy milk samples and the test components are equilibrated to an operating environment between 20 to 40°C. The milk sample must be thoroughly homogenous. Refrain from utilizing samples presenting heavy clumping, murky separation, odd odors, or severe sensory anomalies. For milk powder samples, completely dissolve the powder in distilled water at a strict 1:9 weight-to-volume ratio (e.g., mix 1 g of dry milk powder with exactly 9 mL of distilled water).

Assay Procedure Loop

· Open the main storage vial, remove the required number of test strips and reagent microwells, and apply necessary markings. Re-cap the vial tightly immediately to shield remaining strips from ambient moisture contamination.

· Place the selected microwells onto a standard incubator block. (If the room temperature is securely above 20°C, incubation can proceed directly at room temperature; if below 20°C, set the incubator control precisely at 40°C).

· Pipette exactly 150 µL of the prepared milk sample into the precoated microwell. Mix slowly but thoroughly by repeatedly pipetting up and down. Incubate the mixture for exactly 3 minutes.

· Insert the test strip into the microwell with the sample loading end facing downward and start timing immediately.

· Interpret the visual results exactly at 7 minutes. Visual readouts are strictly invalid after 10 minutes due to post-reaction chemical shifts.

Visual Results Determination Guide

· Negative (-):The T1, T2, T3, and T4 lines all develop strong, distinct red bands whose intensities match or exceed the Control (C) line. This indicates that all four contaminant groups are below the targeted regulatory cutoffs.

· T1 Positive (+):The T1 line is visibly lighter than the C line or disappears completely, while the C, T2, T3, and T4 lines develop normally. This indicates Aflatoxin M1 contamination meets or exceeds the threshold.

· T2 Positive (+):The T2 line is visibly lighter than the C line or fails to appear, indicating that Sulfonamide residues meet or exceed the threshold.

· T3 Positive (+):The T3 line is visibly lighter or absent, confirming that Tetracycline residues meet or exceed the cutoff.

· T4 Positive (+):The T4 line is visibly lighter or absent, confirming that Beta-Lactam residues meet or exceed the cutoff.

· Multiplex Positive (+):Any combination of multiple faded or absent T lines indicates simultaneous contamination of those respective analytes.

· Invalid:The Control (C) line fails to develop a visible color band, regardless of the appearance of any T lines. This indicates an operational error or a compromised strip; re-testing with a brand new strip is required.

Storage & Packing Specifications

· Kit Capacity:96 tests per kit (96 test strips, 96 reagent microwells, and 1 user manual).

· Storage Matrix:Can be stored and transported at room temperature for up to 30 days. For long-term preservation, keep tightly sealed in a refrigerator at 2–8°C for a full shelf-life of 24 months. Do not freeze.