Rapid detection of melamine

Rapid detection of melamine Melamine is abbreviated as triamine and cyanuric amide. It is a widely used organic chemical raw material with nitrogen heterocyclic structure. Because there are many amino nitrogens in its structure, the current quantitative determination of proteins mainly depends on Ky Nitrogen is determined so that melamine is added to the protein by some unscrupulous trader to increase the nitrogen content in the protein assay. The accidental death of cats and dogs and pets in the United States in March 2007 and recent milk powder incidents in the United States all resulted from this. At present, the main methods for the detection of melamine are HPLC, LC-MS, and GC-MS, but the instrument and laboratory requirements are relatively high, and sample handling and operation are relatively demanding. Relatively speaking, the detection kit is easy to operate, does not require large investment of instruments, and also has good sensitivity. Most of these kits use direct competitive enzyme-linked immunosorbent assay (ELISA). The melamine extract obtained from the UD and 60% methanol methods can be used for immunoassay to obtain the same results, which can be used to quantitatively detect contaminated samples. In the melamine.
Detection principle: The melamine detection kit is a competitive enzyme-linked immunosorbent assay. Melamine is extracted from the sample. The melamine-HRP, sample extracts and standards were added together to react in the wells coated with melamine antibody. After 30 minutes incubation, the samples were mixed with melamine and melamine-HRP and melamine antibody, and any unbound melamine was found. And melamine-HRP will be washed away, and the chromogenic enzyme substrate will be added to the microwells. Any combined melamine-HRP will make the liquid blue. The reaction was stopped after 20 minutes and read with a microplate reader. Comparing the reading of the unknown sample with the reading of the standard gives the melamine concentration in the sample.
Required equipment and materials for the experiment:
1. Deionized or distilled water (ZealPure)
2.20-200ul single channel micro sample gun (NPX-200)
3.50-20000ul 8-track micro-loading gun (00-NP7-8L)
4. Plate reader (405nm) (BioTek ELx800)
5. The timer (Casio)
6. Wash bottles (Nalgene)
Testing procedures:
1. Recover all reagents to room temperature and wash the bottles with deionized water;
2. Prepare the required microwell strips;
3. Add 100 μL of each standard or diluted sample extract to the indicated wells and add 50 μL of melamine-HRP;
4. Slightly shake for 60 seconds and culture for 30 minutes;
5. Drain the liquid from the hole, add water to the hole with a pipette, and drain the liquid. Repeat the operation 3 times;
6. Add 100 μL of substrate per well;
7. Incubate for 20 minutes;
8. Add 100 μL stop solution to each well;
9. Read at 450nm reader.
Interpretation of results:
1. Semi-quantitative results can be obtained by comparing the absorbance of a sample with the absorbance of a standard. When the color of the sample is lighter than that of the standard, the concentration of melamine in the sample is higher than that of the standard. If the color of the sample is darker than that of the standard, the concentration of melamine is lower than that of the standard.
2. The quantification can be obtained from the standard curve diagram. The absorbance of the sample is used as the X axis, and the logarithm of the standard concentration is used as the Y axis. Y
The corresponding point on the axis multiplied by the corresponding dilution is the concentration of the sample.

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