• Call +1.858.633.0165 or Fax +1.858.633.0166 or Contact Us

MyBioSource ELISA Test Kits

MyBioSource supplies Enzyme Linked Immunosorbent Assay (ELISA) kits (and custom elisa kit productions) that detect a variety of antigens, proteins and peptides, including EGF, VEGF and various cytokines.

Our extensive catalog includes ELISA kits that can be used to study a variety biochemical pathways and disease states, such as cancer, the insulin signaling pathway and oxidative stress. MyBioSource sells thousands of ELISA kits that are reactive with Human, Mouse, Rat, Bovine, Rabbit, Chicken, Porcine, Monkey, Goat, Sheep, Canine, Guinea Pig samples. We also have many other ELISA kits available that can be used with samples from less common species, such as Horse, Fish, Cat, Hamster, Donkey, Duck, Pigeon, Camel, Goose, Plant, etc.... The majority of our ELISA kits can be used with a wide variety of sample types including serum, plasma and tissue homogenates, as well as cell culture lysates and supernatants.

MyBioSource supplies Enzyme Linked Immunosorbent Assay (ELISA) kits for the detection of numerous antigens, proteins and peptides.
We offer a wide selection of species reactivity (please see below).

Guinea pig

Custom ELISA Kit Production

MyBioSource can produce ELISA Kits for a wide range of targets and species. If you cannot find the target and/or species that you require then please submit your request. Custom ELISA Kit manufacture is also available; kits can be designed and produced to the user's specifications.

Click Here to submit your request! submit your request!

An Introduction to ELISA

The enzyme-linked immunosorbent assay, also known by the acronym, ELISA, was created in the 1970s. This common lab test measures the concentration of an analyte, which is generally antibodies or antigens in a particular solution. With ELISA, quantitative results can be detected, which sets it apart from other similar type tests.

The basic procedure for ELISA begins with a coating step. In this step, a polystyrene plate is covered with a solution that has either antibodies or antigens. The liquid is then dumped and the plate is washed. Next, is the blocking step. In this step, a solution that is protein-based and unrelated to the first solution covers the unbound sites on the plate. Once again, the liquid is removed and the plate is washed off. In the detection step, the enzyme-conjugated antigen or antibody binds to the target antigen or antibody. The plate is then drained and washed again. Finally, a substrate is placed in the plate and the signal given by the reaction of the enzyme and substrate is what is measured.

There are four different types of ELISA tests:
  • Direct: This method is the fastest and has fewer steps. It is also less prone to an error.
  • Indirect: This method has increased sensitivity and it costs less as fewer labeled antibodies are required.
  • Sandwich ELISA: With this method, there are more steps involved. However, the results are highly specific.
  • Competition or Inhibition ELISA: This method is usually used when only one antibody is available or when the analyte is small.

In addition to these different methods to perform ELISA, there are also different detection methods; direct and indirect.

The results of an ELISA test can be quantitative, qualitative, or semi-quantitative. Results are usually graphed to compare it with other results and come to a definitive result. Quantitative results are read in comparison to a standard curve. Qualitative results simply give a yes or a no as to whether or not an antigen is present. Semi-quantitative results are compared in relative levels.

This test is one of the most sensitive immunoassay tests available today. The sensitivity will depend upon the characteristics of the antibody-antigen reaction. To improve the results, the lab can add a substrate, such as those that give an enhanced chemiluminescent or fluorescent signal.

Overview Of The Basic ELISA Procedure

ELISA is the acronym for enzyme-linked immunosorbent assay, which is a popular lab technique used to calculate and assess the presence of an analyte in a sample. In the case of ELISA, the technique is used primarily to determine the concentration of antibodies or antigens in the sample being tested.

The basic ELISA procedure will, unlike other assays that determine concentration of antibodies in blood or any other sample, provide precise quantities of the antibody or antigen in question. ELISA is different because separation of specific interactions and non-specific interactions is achieved through serial binding to a polystyrene multi-well plate.

Another unique feature of the ELISA test is that it can be used to formulate color-coded results with the color of the end product depending on the amount and concentration of the antigens or antibodies in the sample that was tested. This trait makes this procedure a lot easier to understand as compared to other procedures that do not offer the simplicity of color-coded test results.

Other benefits of the ELISA procedure include:
  • The tests can be carried out quickly, which means the patient does not have to wait a long time to undergo the test and receive the results.
  • The ELISA test is a simple one that can be performed in a normal environment without requiring detailed preparation or other procedures.
  • The procedure is designed in such a manner that a large volume of samples can be tested and assessed simultaneously. This makes it a preferred diagnostic procedure when tests have to be conducted in large numbers.

ELISA was developed primarily as an improvement over radioimmunoassay. The basic procedure, which was first introduced in the early 70s, continues to remain in use even today. Of course, newer technologies and better equipment have facilitated the introduction of modified versions of the procedure. The modified versions include Direct, Indirect, Sandwich and Competition, or Inhibition procedures.

These modified procedures offer the following improvements:
  • ELISAs can specifically measure the presence of the target analyte in a single well plate.
  • These procedures offer detailed results with highly-accurate readings of precise parameters.
  • The tests provide direct cell-related or cell-centric output.

Understanding The ELISA Assay Types

Immunoassays are biochemical tests that are used to measure the concentration of an analyte in a solution. They were first invented in the 1950s, and improved upon in the 1960s. They come in a variety of formats.

The enzyme-linked immunosorbent assay (or ELISA as it is more commonly known) was developed in the 1970s and took the place of the radioimmunoassay technique that had been commonly used up until that time. ELISA is typically used as a diagnostic tool by hospitals, clinics and medical laboratories. Various commercial industries also use it as a quality control check method and food industries use it to detect the presence of potential allergens in commercial food products.

The Advantages of ELISA

ELISA sensitivity is higher than that of other immunoassays. What is more, ELISA can provide quantitative results that can enable a doctor, laboratory technician or company manager to see clearly exactly how much of a particular analyte is present in any given solution.

The ELISA testing technique is also quick, as it has been specifically designed to handle a large quantity of samples simultaneously. They are also simple, enabling companies to easily train workers in how to carry out these tests and handle the results from them.

ELISA Test Types

There are three primary ELISA testing methodologies. These are Direct ELISA, Sandwich ELISA and Competitive ELISA. Direct ELISA tests can be run in either a quantitative format or a qualitative one. Qualitative results are listed as either "yes" or "no" while quantitative results compare the optical density of the sample in question to a standard curve. Sandwich ELISA tests detect sample antigen while Competitive ELISA tests are used to detect the presence of the HIV virus and use a slightly different methodology than the ELISA testing methods mentioned above.

The enzyme-linked immunosorbent assay testing method has much to offer. It helps doctors diagnose and treat medical conditions, is used by anti-doping agencies to ensure that athletes are not taking illegal drugs and enables companies to product allergen-free food items for those who need them. ELISA is quick, efficient, and sensitive and offers various testing options to suit the needs of any medical or industry professional.

Defining ELISA Detection Options

In performing an ELISA, enzymes are employed as a label that will produce the ability to detect a signal that indicates an antibody has bound to a specific antigen. The process can use various different types of enzymes and enzyme substrates, with slightly differing methods of incorporating them. Depending on the substrate selected, either a florescent or spectrophotometric plate reader can measure the signal to achieve the final assay.

The two ELISA detection options, indirect and direct, largely determine the sensitivity of an ELISA measurement. However, the terms for the strategies can be confusing because they can have various applications. For our purposes, the terms, when applied to the detection portion of the ELISA, will be defined as follows:

Direct detection refers to the most common strategy of this type in use. This involves directly labeling antibodies using horseradish peroxidase (HRP) or alkaline phosphatase (AP) substrate. These will produce a color reagent that will allow colorimetric measurement by a spectrophotometer. A fluorescence-linked immunosorbent assay also can be attained using antibodies that are fluorescent-labeled.

Direct detection is quick, needing fewer steps to achieve. In addition, cross reaction of a secondary antibody is eliminated. However, the process allows only minimal amplification of the signal. It also can be time consuming when each specific ELISA system requires the labeling of primary antibodies.

Indirect detection of the most common type involves the coupling of antibodies to biotin, which is followed up by applying a streptavidin-conjugated enzyme. The use of primary antibodies that are unlabeled also is possible when followed with biotinylated or enzyme-coupled secondary antibodies. Another step is needed for detection, however, if a biotinylated secondary antibody is used, requiring in this case a streptavidin-conjugate treatment with a suitable substrate.

Indirect detection is the most often used format for ELISA. It affords the use of an extensive variety of labeled secondary antibodies that are available on the commercial market. It also offers versatility, since that same labeled antibody can be used for detection with many primary antibodies that are made in a single species. Signal amplification can readily be achieved, so sensitivity is enhanced. However, there is the chance for cross-reactivity with the secondary antibody, which can create a non-specific signal. The process also requires an additional incubation step.

ELISA Results

Elisa results figure 1

ELISA, short for enzyme-linked immunosorbent assay, is a commonly used laboratory test that measures the amounts of an analyte within a solution. In most cases, the analyte is usually an antigen or an antibody. The basic ELISA test is different from other anti-body based assays due to their separation of specific and non-specific interactions that occur with serial binding to a polystyrene multi-well plate, or another solid surface type.

The ELISA assay was created in the 1970s and replaces radioimmunoassays. The benefits of ELISA include that it is relatively easy to perform and they can be performed with large samples in parallel. Because of these benefits, ELISA is widely used by researchers and for diagnostic targets. The original form of ELISAs is still being used today. However, there are expanded and modified forms that can involve several analytes per well, direct cell-based output, and highly sensitive readouts.

ELISA tests are based upon the specific interaction between a sequence of amino acids found on an antigen and an antibody binding site that matches. The antibodies utilized for an ELISA test can be monoclonal or polyclonal.

ELISA results yield three different types of data:
  • Quantitative: With quantitative data, the results are interpreted by comparing them to a standard curve, which allows the concentrations of antigens in different samples to be precisely determined.
  • Qualitative: Qualitative data either confirms or denies whether the presence of a particular antigen is in a sample. This data is a yes or a no answer and is used in comparison to a blank well that does not contain an unrelated control antigen or any other antigen.
  • Semi-quantitative: The intensity of a signal can differ directly based on antigen concentration. ELISA data can be used to compare the relative levels of antigens within an assay sample.

Usually, data from ELISA assays are graphed using optical density vs. log concentration. This will reveal a sigmoidal curve. Any known concentrations of antigen are utilized to give the standard curve on the graph. Then, that data can be used to measure the concentration of the unknown samples when compared to the linear portion of the standard curve. Graphing can be accomplished on paper or with curve fitting software that can usually be found on ELISA plate readers.

Information On ELISA And ELISA Sensitivity

ELISA is essentially a diagnostic tool that is often used in plant pathology and medicine. It is also used in various industries as a tool for quality control. It involves the detection of the specific substance (or analyte) being analyzed quantitatively or qualitatively in a liquid sample. This technique continues to use liquid reagents throughout the process of the evaluation. The reagents remain in its liquid form and stays inside a reaction chamber. They also function to contain the reactants.

ELISA is a heterogenous assay that separates some components of the analytical reaction mixture. Adsorbing particular components onto a solid, physically immobilized phase does this. In ELISA, a solid phase has special binding properties on which a liquid sample is placed. This is followed by the sequential adding of multiple liquid reagents, incubating and washing of the reagents. There will be some optical change of the liquid in the well. The presence of analyte will then be measured from this liquid.

This will generate a qualitative reading typically based on the discovery of the concentration of transmitted light through spectrophotometry. This involves quantifying the transmission of certain specific light wavelength through the liquid. The sensitivity of discovery depends on how the signals are amplified during analytic reactions. Enzyme reactions are well-known amplification processes. Additionally, enzymes produce the signal that is linked to the reagents in fixed proportions. This enables accurate quantification.

ELISA Sensitivity

ELISAs are among the most sensitive immunoassays available. They have a typical detection range between 0.01 ng and 0.1 ng or 0.1 and 1 fmole. ELISA sensitivity relies on the specific characteristics of the interaction between the antibody and the antigen. Additionally, a number of substrates, like the ones yielding fluorescent signal or enhanced chemiluminescent, can be utilized to enhance results. Indirect detection will generate higher levels of signal and as such, should have more sensitivity. However, it can also result in elevated background signal that reduces net specific signal levels.

ELISAs are carried out quickly and easily. They are designed to speedily handle a large amount of parallel samples. Therefore, they are a commonly used to analyze a number of different research and diagnostic targets.

ELISA Kit Protocol

The manuals for our ELISA kits are either linked on our online datasheets or available upon request. These documents include information regarding the principle of the assay, a complete list of the contents included in the kit and a detailed protocol. The easy to follow protocol and detailed instructions are ideal for those who have a limited familiarity with ELISAs, as well as those who are very familiar with the technique but are short on time. MSDS documents for our products are also available upon request. There are many ELISA kit companies and manufacturers that provide a broad range of assays, but what makes our kits different are the quality components and reagents.

ELISA Kit Pricing

MyBioSource is committed to providing high quality ELISA kits at reasonable prices. The cost of our ELISA kits is comparable to that of other leading manufacturers, such and Sigma and R&D Systems. Also, our kits are only assembled when an order is placed to ensure that all of the reagents will be fresh and to extend the shelf life for our customers. MyBioSource's knowledgeable sales staff is always happy to answer any questions that you may have. Our company is committed to providing efficient and friendly customer service. You can purchase our products online, by faxing your order to 1.858.633.0166 or by sending an email to sales@mybiosource.com. We look forward to hearing from you soon!

Request a Quote

Please fill out the form below and our representative will get back to you shortly.

Contact Us

Please fill out the form below and our representative will get back to you shortly.