What is the Difference Between Sandwich Elisa and Competitive Elisa?
🆚 Go to Comparative Table 🆚The main difference between sandwich ELISA and competitive ELISA lies in the way the antigen is detected and the number of antibodies used. Here are the key differences:
Sandwich ELISA:
- Requires two antibodies specific for different epitopes of the antigen.
- One antibody is coated on the surface of the multi-well plate and used as a capture antibody, while the other antibody is conjugated and facilitates the detection of the antigen.
- Highly sensitive and robust, as the antibody binds to two sites on the antigen.
- Suitable for analyzing complex samples, such as tissue culture supernatants or tissue lysates.
- Has a lower risk of cross-reactivity and non-specific binding.
Competitive ELISA:
- Requires only one antibody for the detection of the antigen of interest.
- Used when there is only one antibody available to detect the antigen, or when the protein of interest is too small to efficiently sandwich with two antibodies.
- Less sensitive than sandwich ELISA.
- Commonly used for small molecules and assessing antibody affinity and specificity.
- Faster, more flexible, and has good reproducibility, but may be less sensitive to experimental errors.
In summary, sandwich ELISA is more sensitive and specific, requiring two antibodies for the detection of the antigen, while competitive ELISA uses only one antibody and is suitable for small molecules or when only one antibody is available.
On this pageWhat is the Difference Between Sandwich Elisa and Competitive Elisa? Comparative Table: Sandwich Elisa vs Competitive Elisa
Comparative Table: Sandwich Elisa vs Competitive Elisa
Here is a table comparing the differences between Sandwich ELISA and Competitive ELISA:
Parameter | Sandwich ELISA | Competitive ELISA |
---|---|---|
Purpose | Detect and quantify antigens in immunoassays | Detect and quantify antibodies in immunoassays |
Antibodies | Uses two antibodies specific to the same protein but at different epitopes | Uses two antigens, one immobilized and the other in the sample |
Sensitivity | More sensitive and robust due to the antibody binding to two sites on the antigen | Less sensitive to experimental errors, but generally less sensitive than sandwich ELISA |
Specificity | High specificity as two antibodies are used to detect the antigen | Detection signal inversely correlates with the amount of antigen in the sample |
Sample Preparation | Analyte does not need to be purified prior to the assay | Requires only one antibody to detect the antigen |
Application | Suitable for analyzing complex samples, such as tissue culture supernatants or tissue lysates | Useful for detecting small antigens with only a single antibody epitope |
Cross-Reactivity | Risk of cross-reactivity and non-specific binding | Less risk of cross-reactivity and non-specific binding |
Sandwich ELISA is commonly used to detect and quantify antigens in immunoassays, while Competitive ELISA is commonly used to detect and quantify antibodies in immunoassays.
Read more:
- Competitive vs Noncompetitive ELISA
- Elisa vs Western Blot
- ELISA vs Rapid Test
- Direct vs Indirect ELISA
- RIA vs ELISA
- Elisa vs Elispot
- Serum Protein Electrophoresis vs Immunofixation
- Antiserum vs Antibody
- Antigen vs Antibody Test
- Capillary Electrophoresis vs Gel Electrophoresis
- SDS Page vs Western Blot
- Cell Immobilization vs Enzyme Immobilization
- Immunoglobulin vs Antibody
- Fluid Mosaic Model vs Sandwich Model
- Competitive vs Noncompetitive Inhibition
- Antibodies vs T Cells
- Serum vs Antiserum
- Antigen vs Antibody
- Monoclonal Antibodies vs Polyclonal Antibodies