Food intolerance test kit 20010

for food safetyfor animalsfor nitrofurane

Introduction
The Nitrofuran (SEM) rapid test dipstick is a competitive inhibition immuno-chromatographic assay for qualitative screening of Nitrofuran (SEM) residues in food tissue samples. During sample migration the SEM in the sample competes with SEM–BSA conjugate on the test line for colloidal gold-labeled monoclonal antibody binding; this competition causes a change in the test (T) line intensity. The control (C) line must appear for a valid result.

Specifications
96 strips per kit; for tissue samples (poultry, livestock, fish and seafood).

Brief
Designed for rapid, on-site or laboratory screening of Nitrofuran (SEM) residues in homogenized tissue. Simple workflow and high analytical sensitivity facilitate routine monitoring and pre-screening before confirmatory analysis.

Sample performance

• Poultry and livestock tissues: pork, beef, sheep, chicken, duck, goose and related tissues
• Fish and seafood: freshwater and marine fish, shrimp, crab and similar tissues

Detection limit
Tissue: 0.5 μg/kg (ppb)

Contents

• 12 bottles containing test dipsticks, desiccant and micro-wells (total 96 strips)
• Manual — 1 pc
• 1M HCl — 2 bottles
• 1M NaOH — 2 bottles
• 1M K2HPO4 solution — 2 bottles
• Derivatization reagent — 1 bottle
• Sample buffer — 2 bottles

Principle
The assay is based on competitive inhibition immuno-chromatography: SEM in the sample binds the colloidal gold-labeled monoclonal antibody during migration, preventing its binding to SEM–BSA conjugate at the T line. If SEM is absent or below the detection limit, the T line intensity is equal to or darker than the C line; at or above the detection limit the T line is noticeably lighter or absent. The C line confirms test validity.

Sample preparation

• 1) Place 5 ± 0.05 g homogenized tissue into a 50 ml centrifuge tube; add 4.5 ml deionized water, 1.5 ml Reagent A and 300 µl Reagent B; shake 2 min, then incubate in a 75℃ water bath for 5 min.
• 2) Add 7 ml Reagent C, shake 1 min; add 6 ml ethyl acetate, shake 1 min, centrifuge 4000 r/min for 5 min.
• 3) Transfer 3 ml of the upper layer to a 10 ml tube and evaporate to dryness at 75℃ under nitrogen or air.
• 4) Add 1 ml Reagent E, dissolve residue; add 1 ml Reagent F, shake 30 s, allow phase separation and collect the upper layer (centrifuge if emulsion appears).
• 5) Pipette 200 µl of the lower aqueous layer for testing (avoid organic upper layer).

Operation procedures

• 1) Read instructions and equilibrate dipsticks and samples to room temperature.
• 2) Open required bottle, take necessary microwells and dipsticks; use dipsticks within 1 hour of opening and reseal to prevent moisture.
• 3) Add 200 µl prepared sample to microwell and aspirate 5–10 times to mix until no visible solids remain.
• 4) Incubate 5 min at 20–25℃, then insert dipstick with the MAX mark fully immersed.
• 5) Incubate 5–8 min at room temperature and read result within this window; readings outside this time are invalid.

Test result interpretation

• Negative: T line darker than or equal to C line — SEM absent or below detection limit.
• Positive: T line obviously lighter than or absent compared with C line — SEM at or above detection limit.
• Invalid: C line absent — invalid test (expired, damaged or improper operation). Repeat with a new strip.

Technical specifications

• Product: Nitrofuran (SEM) rapid test dipsticks for tissue
• Kit format: 96 strips per kit (12 bottles)
• Supported samples: poultry, livestock, fish and seafood tissues
• Method: Competitive inhibition immuno-chromatographic assay with colloidal gold-labeled monoclonal antibody
• Detection limit (tissue): 0.5 μg/kg (ppb)
• Total assay time: pre-incubation 5 min + dipstick incubation 5–8 min (read at 5–8 min)
• Kit contents: dipsticks, reagents (HCl, NaOH, K2HPO4, derivatization reagent, sample buffer), microwells, manual