Enzyme-Linked Immunosorbent Assay (ELISA) is used mainly to detect and quantify proteins, antibodies, peptides, or hormones in a sample. In ELISA, antigens are immobilized on a solid support, either coated directly or through specific capture antibodies. Primary detection antibodies are then applied, forming a complex with the antigen. If conjugated with an enzyme, the detection antibody can directly be used to quantify the antigen, or can itself be quantified by another enzyme-conjugated secondary antibody. The method chosen depends on which target you are investigating.

Types of ELISA Methods:

    • Direct ELISA:
      Antigens are immobilized and enzyme-conjugated primary antibodies are used to detect or quantify antigen concentration. The specificity of the primary antibody is very important.
      • PROS: minimum procedure; avoids cross-reactivity from secondary antibody.
      • CONS: requires labeling of all primary antibodies - high cost; not every antibody is suitable for labeling.


    • Indirect ELISA:
      Primary antibodies are not labeled, but detected instead with enzyme-conjugated secondary antibodies that recognize the primary antibodies.
      • PROS: secondary antibodies are capable of signal amplification; many available secondary antibodies can be used for different assays; unlabeled primary antibodies retain maximum immunoreactivity.
      • CONS: cross-reactivity may occur.


    • Sandwich ELISA:
      The antigen to be measured is bound between a layer of capture antibodies and a layer of detection antibodies. The two antibodies must be very critically chosen to prevent cross-reactivity or competition of binding sites.
      • PROS: sensitive, high specificity, antigen does not need to be purified prior to use.
      • CONS: antigens must contain at least two antibody binding sites.


  • Competitive ELISA:
    The antigen of interest from the sample and purified immobilized antigen compete for binding to the capture antibody. A decrease in signal when compared to assay wells with purified antigen alone indicates the presence of antigens in the sample.
    • PROS: crude or impure samples may be used, high reproducibility.
    • CONS: lower overall sensitivity and specificity.

Antibody Product Showcase

Antibody Pair for ELISA PEG Matched Antibody Pair
Antibody pairs for quantitative detection of proteins. Antibody pair to detect and quantify PEGylated compounds.
Angiogenesis ELISA Kits Apoptosis ELISA Kits
ELISA kits for angiogenesis research. ELISA kits for studying programmed cell death in multicellular organisms.
Autoimmune ELISA Kits Binding ELISA Kits
ELISA kits for analysis of autoimmune diseases. ELISA kits for quantitative detection of binding proteins.
CD Marker ELISA Kits Cell Ad/Junc/Cytoskel ELISA Kits
ELISA kits to identify and investigate cell surface molecules. ELISA kits for analysis of cell adhere/junction and cytoskeleton.
Cell Cycle ELISA Kits Cytokine ELISA Kits
ELISA kits for quantitative detection of cell cycle processes. ELISA kits for analysis of cytokine proteins.
Diabetes ELISA Kits Down-Syndrome ELISA Kits
ELISA kits for diabetes research. ELISA kit for investigating Down Syndrome.
Enzyme ELISA Kits Immunoglobulin ELISA Kits
ELISA kits for analysis of different enzymes. ELISA kits for analysis of different immunoglobulins.
Infectious ELISA Kits Interleukin ELISA Kits
ELISA kits to investigate infectious diseases. ELISA kits for analysis of interleukins.
Membrane ELISA Kits Metabolism ELISA Kits
ELISA kits associated with membrane proteins. ELISA kits targeting metabolism.
Neurobiology ELISA Kits Plasma/Serum ELISA Kits
ELISA kits for neurobiology related research. ELISA kits for analysis of proteins in plasma and serum.
Signal Transduction ELISA Kits Small Molecule ELISA Kits
ELISA kits for investigating signal transduction pathway. ELISA kits for analysis of small molecules.
Stem Cell ELISA Kits Other ELISA Kits
ELISA kits for stem cell research. ELISA kits for a wide range of miscellaneous proteins.


Indirect ELISA

The indirect ELISA is used primarily to determine the strength and/or amount of antibody response in a sample. In the assay, the antigen of interested is immobilized by direct adsorption to the assay plate. Detection of the antigen can then be performed by using a matched set of primary antibody and conjugated secondary antibodies.

Publish: 2010/04/26 Time: 4:15

Sandwich ELISA

The Sandwich ELISA measures the amount of analyte between capture antibody and detection antibody. The analyte needs to have two different epitope sites available for antibody binding.

Publish: 2010/02/12 Time: 3:40

Sandwich ELISA-Isotype Detection

Sandwich ELISA is performed to determine the amount and serological class of antibodies made by an immunized animal or present in the serum of patients. The anti-immunoglobulin antibodies used have high specificity and sensitivity.

Publish: 2010/06/30 Time: 3:50

Competitive ELISA

In competitive ELISA, unlabeled antibody is incubated in the presence of its antigen. Then these bound antibody/antigen complexes are then added to an antigen coated well. After washing, unbound antibody is removed. The more analyte in the sample, the less antibody will be able to bind to the antigen in the well. The signal is then detected using a labeled secondary antibody and the decrease in signal is compared to a control. The major advantage of a competitive ELISA is the ability to use crude or impure samples and still selectively bind any antigen that may be present.

Publish: 2010/05/03 Time: 3:22



[Brochure] Antibody Pairs for ELISA, IP-WB, Protein Phosphorylation, Protein-Protein Interaction.
[Brochure] ELISA and Assay Kits.
[Flyer]Antibody Pair for ELISA.
[Flyer]Antibody Pair for PEG.