Enzyme-linked immunosorbent assay (ELISA) is one of the most popular immunoassay formats due to its flexibility, sensitivity, and ease of use. Additionally, the relatively low cost of ELISA and its applicability to high-throughput testing make it an ideal solution to many different research and in vitro diagnostic (IVD) needs. ICL offers a broad range of ELISA kits for human and animal research, as well as an extensive selection of antibodies and proteins for those wishing to develop their own ELISA in-house. All our products are manufactured in the USA and subject to rigorous testing for quality and consistency to ensure results you can trust.
What is an ELISA?
ELISA is a microplate-based assay used for capturing a target analyte from solution. It can be configured in several different ways, with the chosen format being dependent on the aim of the study. During a direct ELISA, the analyte is bound to the microplate wells and is then detected with an enzyme-labeled analyte-specific antibody. Although quick and easy to run, direct ELISA has only limited sensitivity; using an enzyme-labeled secondary antibody for indirect detection is a popular approach to achieve signal amplification. Rather than requiring that the antigen be bound to the microplate, sandwich ELISA instead uses matched antibody pairs for analyte capture and detection. This method benefits from superior specificity and sensitivity over direct ELISA, provided the antibody pair has been validated for the ELISA application; not only must the two analyte-specific antibodies recognize different epitopes to prevent them competing for analyte binding, but they must also be shown not to cross-react with each other to avoid producing unwanted background signal. Another ELISA format, competitive ELISA, involves competition between the target analyte and a reference for binding to a known amount of labeled antibody or protein.
Reagent considerations for ELISA
Primary antibodies are critical reagents for ELISA and must demonstrate high specificity for the target analyte to ensure accurate results. Another factor to consider is the clonality; while monoclonal antibodies benefit from consistent lot-to-lot performance and guaranteed long-term supply, polyclonals can provide signal amplification by recognizing multiple epitopes and are typically available sooner when a novel target is discovered. Labeled secondary antibodies are equally important and should be matched to the host species of the primary antibody for a measurable signal to be produced. Where the ELISA will use reagents from multiple species (e.g., combining antibodies from several different hosts for multiplexed detection or employing BSA as a blocking agent), using cross-adsorbed secondary antibodies can help prevent non-specific background signal. Proteins function as essential controls to show that an ELISA is performing as expected and are also used as reference standards for analyte quantification. For reliable results, proteins should be of high purity and proven to have minimal batch to batch variability. Likewise, accessory reagents such as blocking buffers and antibody diluents should be provided with data demonstrating product quality.
What are the benefits of using an ELISA kit?
Using an off-the-shelf ELISA kit can save researchers significant amounts of time and money compared to developing and optimizing an assay in-house. A main reason for this is that the product will have undergone exhaustive testing by the manufacturer to safeguard performance, including characterization of matched pair antibodies to minimize the risk of unwanted binding effects. Where the manufacturer produces the raw materials for ELISA in-house, researchers can be further assured of consistent product quality and uninterrupted supply.
High-sensitivity ELISA kits
ICL offers a broad selection of ELISA kits for measuring different protein markers in various species and biological sample types. All of these are based on sandwich detection for high sensitivity and undergo rigorous testing to ensure consistent performance with minimal batch to batch variability. Our Human IgG ELISA Kit is one of our most popular products, boasting a long list of citations, and is compatible with sample types including milk, plasma, serum, urine, and tissue culture supernatant .
Why choose ICL?
Using our own raw materials for ELISA kit manufacturing means we retain complete control over our products, making us the ideal partner to support your research. But don’t just take our word for it – our customers include many of the world’s leading IVD manufacturers, pharmaceutical companies, and research institutions, and our ELISA kits have been widely cited in the literature across multiple fields of research. With a strong technical support team and rapid customer service, you can count on us for high quality ELISA kits that deliver results you can trust.
