Capture operation is a necessary condition to ensure accurate and reliable ELISA results - Database & Sql Blog Articles

High-quality reagents, proper instrumentation, and precise operation are all essential for obtaining accurate and reliable ELISA results. The method of ELISA can vary depending on the type of solid-phase carrier used. In domestic medical testing, plate-based methods are commonly applied. This article will focus on the key points of the capture method. Following detailed instructions and strictly adhering to the protocol ensures accurate outcomes. The test in the ELISA kit found that:

Specific IgM and specific IgG antibodies against certain antigens can coexist in serum, which may interfere with the detection of IgM antibodies. To address this, the multi-capture method for IgM antibodies was developed. This approach involves first immobilizing all IgM in the serum (both specific and non-specific) onto a solid phase, then removing IgG before determining the specific IgM. Below, we will walk you through the detailed steps of this process. Please continue reading!

(1) A solid-phase anti-human IgM antibody is coated onto the carrier surface. After incubation, the plate is washed to remove unbound materials.

(2) Diluted serum samples are added. During incubation, the IgM antibodies in the serum bind to the solid-phase anti-IgM. After washing, impurities and other immunoglobulins are removed.

(3) A specific antigen reagent is introduced. It binds only to the specific IgM attached to the solid phase. Following another wash, the unbound material is discarded.

(4) An enzyme-labeled specific antibody is added. It reacts with the antigen-bound IgM on the solid phase. After washing, the unbound enzyme-labeled antibody is removed.

(5) A substrate is added. If a color develops, it indicates the presence of specific IgM antibodies in the sample, resulting in a positive reaction.

Commonly used ELISA methods include the following:

I. Double Antibody Sandwich Assay for Antigen

An antibody produced by immunizing an animal with an antigen is adsorbed onto the solid phase surface.

Then, the antigen is added, forming an antigen-antibody complex.

A second antibody, raised in a different animal, is added, binding to the antigen-antibody complex.

An enzyme-labeled secondary antibody is introduced, which binds to the second antibody.

Finally, the substrate is added. The degree of substrate degradation reflects the amount of antigen present.

II. Direct Method for Antigen Detection

The antigen is adsorbed onto the solid support surface.

An enzyme-labeled antibody is then added, forming an antigen-antibody complex.

The substrate is added, and the amount of substrate degradation corresponds to the antigen concentration.

III. Indirect Method for Antibody Detection

The antigen is adsorbed onto the solid support.

An antibody is added, forming an antigen-antibody complex.

An enzyme-labeled secondary antibody is introduced, which binds to the primary antibody.

The substrate is added, and the level of substrate degradation reflects the antibody concentration.

Our ELISA kits offer several advantages:

High specificity: Extensive cross-reactivity studies were conducted to minimize errors caused by non-specific interactions.

High precision: Spike recovery and linear dilution experiments ensure accurate results, with lower CV values than many similar products.

Good repeatability: Lot-to-lot consistency ensures minimal variation between batches.

High reliability: Optimized components reduce the risk of false positives or negatives.

Standard curve: A wide detection range ensures accurate data across various concentrations.

Cost-effective: Using original imported RD reagents with domestic packaging allows us to offer high-quality products at competitive prices, reducing concerns about high costs of domestic kits.