ELISA Plates: Types, Formats & Applications

ELISA Plates: Types, Formats & Applications

ELISA Plates: Overview

Enzyme-linked immunosorbent assay, or ELISA, is a plate-based gold standard immunoassay used in life sciences and molecular biology labs to detect and quantify biomolecules in a complex mixture.

The ELISA assay is a type of immunoassay.

In this technique, antigens are immobilized on the surface of 96 or 384 ELISA well plates. Then, the plate is incubated with antigen-specific antibodies, which bind to the target antigen present at the bottom of the microplates.

ELISA plates reside at the heart of the ELISA assay. They are also known as microtiter plates or microplates and are made from polystyrene or polypropylene. Today, a variety of ELISA plates or microplates are available in the market to suit different lab workflows. Therefore, to develop precise, accurate, and sensitive bioassay, it’s essential to select the right plate, thus, the right surface for immobilizing your target biomolecules.  

In this article, we will cover more of the features of the ELISA microplates, their formats commercially available in the market, and their diverse applications.

Need new or refurbished lab equipment? Excedr leases.

See our equipment list and browse a sample selection of what we can source. Or, if you’re ready, request an estimate.

ELISA Plate Formats

ELISA plates come in various formats, each tailored to specific assay requirements and detection methods. The surfaces of each ELISA well microplate possess a high-binding affinity for a specific biomolecule.

Affinity Immunoassay Plates

Affinity immunoassay plates are developed to enhance the binding of antigens and antibodies. It provides a high-affinity surface for immobilizing biomolecules for increased assay sensitivity, accurate quantification, and optimal interaction.

The plates are used for ELISA and immunoassays. They are coated with nickel, streptavidin, antibody, and other ligands. It’s of variant types, which include:

  • Biotin Binding Plates: These include NeutrAvidin-coated plates and streptavidin-coated plates. These plates are commonly utilized in assays where biotinylated molecules (such as antibodies or nucleic acids) are used as probes or detection agents.
  • Antibody Binding Plates: The different types of antibody binding plates include Protein A/G/L-coated plates and secondary antibody (GAM, GAR)-coated plates. They bind to various classes of immunoglobulins (Iggs, such as IgG, IgM, and IgA) and primary antibodies and are used for efficient antigen detection.
  • His Tag-Binding Plates: Nickel- and copper-coated plates are some types of His tag-binding plates. They are widely used in assays involving histidine-tagged proteins. The His tag-binding plates enable specific immobilization and detection of His-tagged proteins.
  • GST-Binding Plates: It includes glutathione (GSH)-coated plates that are used for the detection and analysis of GST-tagged or glutathione S-transferase (GST) fusion proteins.

Absorption Immunoassay Plates

The absorption immunoassay plate is also known as the binding immunoassay plate. The plates are developed for passive adsorption (coating) of proteins, antibodies, and other biomolecules. They are designed to specifically target the antigen of interest.

It’s also two types:

  • Hydrophilic, Protein-Binding Plates: They are designed to absorb biomolecules in hydrophilic nature, such as glycoproteins, antibodies, glycans, and other soluble proteins.
  • Hydrophobic, Lipid-Binding Plates: They are designed to absorb biomolecules in hydrophobic nature, such as lipids and lipoproteins.

Covalent Immunoassay Plates

These specially designed microplates enable the covalent attachment of peptides, nucleic acids, and other biomolecules. They possess the ability to bind with various functional groups, including amino (NH2), sulfhydryl (SH), carboxyl (COOH), and phosphate (PO4), facilitating stable and efficient immobilization. They have applications in ELISA and other plate-based assay techniques.

One example of covalent immunoassay plates is nucleic acid assay plates. They are available in different types to accommodate the binding of oligonucleotides with various functional groups or tags. These plates allow for strong connections through either covalent bonding or affinity interactions, ensuring accurate and reliable analysis of nucleic acids in experiments.

How Do ELISA Plates Work?

ELISA plates are essential materials in immunology and diagnostic labs that perform the ELISA assay regularly. It ensures the binding of the target antigen and holds the chemistry between the target analyte and antibodies.

To develop an effective immunoassay, it’s crucial to coat ELISA plates with the appropriate protein or antibody. Selecting the appropriate microplate type based on the desired detection signal is essential for achieving optimal plate coating.

The choice of color of the assay microplate depends on the signal being detected. For example, black or white opaque plates are used for chemiluminescent and fluorescent signals, and clear polystyrene flat-bottom plates are used for colorimetric signals.

Ensure the plates are scratch free so they don’t interfere with the analysis and final results.

The coating process involves passive adsorption, where the protein or antibody is added to the plate and allowed to bind to the plastic surface. Typically, a solution of the protein or antibody is prepared and incubated on the plate for a specific period. After incubation, the coating solution is removed, and a blocking buffer is added to prevent nonspecific binding.

It’s important to note that the optimal coating conditions and binding capacity can vary depending on the specific protein or antibody used. Experimentation is often required to determine the appropriate coating concentration. Coating plates with slightly more protein than required allows for a wider range of detection, although excessive coating can lead to nonspecific binding and high background signals.

Once the plates are coated, they can be used immediately or stored at 4°C for future use, depending on the stability of the coated protein. Proper storage conditions ensure the reliability and reproducibility of the assay results.

What Are ELISA Plates Used For?

ELISA polystyrene microplates have a range of applications in research, clinical, and diagnostic labs and industries. It enables researchers to quantify the presence and concentration of target molecules in samples, such as blood, serum, plasma, urine, or cell lysates.

The plates have numerous wells or compartments that allow for simultaneous assessment of multiple samples or test conditions. They allow for high-throughput screening, enabling researchers to process multiple samples efficiently.

ELISA plates are compatible with various detection methods, including colorimetric, fluorescent, and chemiluminescent techniques, offering flexibility in detecting and measuring the antigens of interest.

ELISA Testing

ELISA is one of the most common and widely used plate-based immunoassay techniques used in labs. Other than microcentrifuge tubes and pipets, the assay requires 8-well strip, 96- or 384-well ELISA medium binding or high-binding plates. They allow simultaneous assessment of multiple biomolecules.  

For researchers working with tissue culture or cell-based assays, the medium-binding ELISA plates provide an optimal surface for cell adhesion and growth.

When incubating and washing plates, it is essential to properly seal them to prevent cross-contamination and maintain the integrity of your samples. Plate sealers can simplify this process.

When working with ELISA plates, consider the substrate used for signal generation. Different substrates offer various detection options, including colorimetric and chemiluminescent signals, allowing you to choose the most suitable method for your experimental needs.

Don’t have the budget to purchase lab equipment outright? Consider leasing through Excedr to save your lab time and money. Browse your leasing options today!

Procure Your R&D Lab Needs with Excedr

ELISA plates are polystyrene or propylene-made 96- or 384-well microplates used in labs to analyze many biomolecules simultaneously. These plates enable reliable and accurate detection of target molecules due to their high-binding capabilities. The applications that involve the use of ELISA plates include ELISA assay and other immunoassays.

Other than ensuring the quality and right surface of the ELISA plate, the accuracy and reproducibility of results depend on the use of high-quality reagents paired with high-throughput equipment to perform workflows.

However, all this can be expensive in your pocket and can make you break the bank.

But, we have a solution that can save you from this trouble — Excedr’s comprehensive leasing solution.

Our leasing program allows you to acquire a range of life sciences equipment, including analytical, life sciences and biotech, clinical, and other biology equipment on lease. There’s no requirement for large upfront investment or unwanted and expensive repair and maintenance charges. Further, with this leasing solution, you can acquire any number of equipment or outfit your whole lab.

Leasing equipment through Excedr also ensures that you can stay up-to-date with the latest technology advancements without worrying about equipment obsolescence. This means you can utilize high-binding ELISA plates and other advanced equipment to enhance your research and testing processes.

All this while minimizing financial risks and maximizing operational efficiency!