Working principle of procalcitonin assay kit

The working principle of the procalcitonin (PCT) assay kit is mainly based on immunochromatography technology, especially the double antibody sandwich method and colloidal gold immunochromatography principle or fluorescence immunochromatography principle. The following is a detailed explanation of the working principle:

1、 PCT assay kit based on colloidal gold immunochromatography principle

Composition structure:

A reagent kit usually contains a detection card, which is composed of a test strip housing and a test strip. The test strip is further composed of a sample pad, a gold label pad (fixed with colloidal gold labeled PCT monoclonal antibody 1), a nitrocellulose membrane (coated with PCT monoclonal antibody 2 and sheep anti mouse IgG polyclonal antibody), absorbent paper, and PVC adhesive plate.

Testing process:

When a sample (such as serum or whole blood) is added to the detection card, the procalcitonin (PCT) in the sample will bind to the colloidal gold labeled PCT monoclonal antibody 1 on the gold label pad.

The combined complex diffuses to the detection zone on the nitrocellulose membrane during the chromatography process and is captured by PCT monoclonal antibody 2 encapsulated in this zone, forming a double antibody sandwich complex.

As the concentration of procalcitonin increases, the accumulation of complexes on the detection line increases, and the resulting signal intensity also increases accordingly.

The colloidal gold quantitative detector will automatically calculate and display the concentration of procalcitonin based on the signal strength.

2、 PCT assay kit based on fluorescence immunoassay principle

Testing process:

Mix the detection buffer and sample in a detection bottle, and the fluorescently labeled anti PCT antibody in the detection solution binds to the PCT antigen in the sample to form an antigen antibody complex.

When the mixed sample drops onto the reaction plate and diffuses through capillary action onto the detection line of the nitrocellulose membrane, the complex is captured by the PCT antibody on the detection line.

The more PCT in the sample, the more complex accumulates on the detection line, and the stronger the signal intensity of the fluorescent antibody.

After processing with HMF-D dry immunofluorescence analyzer, the concentration of PCT in the tested sample can be determined.

summary

Whether based on the principle of colloidal gold immunochromatography or fluorescence immunochromatography, the core of PCT assay kits is to quantitatively detect the PCT content in samples by binding specific antibodies to PCT antigens. These test kits have important clinical application value in the early diagnosis, differential diagnosis, and treatment monitoring of bacterial infections, sepsis, and other diseases.