How to Choose a Good ELISA Kit
The ELISA (enzyme-linked immunosorbent assay) is recognized by scientists for its many advantages. The assay is convenient, quick, and simple to execute. ELISA’s versatility to detect peptides, proteins, antibodies, and hormones, and its ability to generate quantitative and qualitative data make it one of the most popular and powerful immunoassays available.
In response to popular demand, numerous commercial ELISA kits are offered in the market, but not all ELISA kits are created equal.
How do we sift through the masses and choose a good ELISA kit?
Keep in mind the following points next time you go hunting for an ELISA kit.
What would you like to determine for your sample? There are four categories of ELISAs - direct, indirect, sandwich, and competitive.
If you’re planning for speedy detection of immune response to an antigen, and signal amplification isn’t a priority, direct ELISA might be for you.
For better sensitivity and greater flexibility to figure out the total antibody concentration, indirect ELISA might be more suitable.
What if your sample is complex? Fear not, choose sandwich ELISA for high sensitivity, specificity, and flexibility without the need to purify the antigen.
Got a sample with small antigens? Competitive ELISA will detect the antigens that are too small for two different antibodies to bind to.
Sample Species & Type
Commercial ELISA kits for commonly used species, such as human, mouse, and/or rat, are readily available. For more unique species like monkey, canine, or porcine, there will be a limited number of available ELISA kits. In this case, choose the kit that has been validated for species that show homology with your sample species. As a rule of thumb, if the sequences are 90%+ identical, there is a high chance of cross-reactivity for your species of interest.
Always check to see if your sample type has been validated by the manufacturer. ELISA kits can be validated for a wide range of samples, including cell culture supernates, serum, plasma (heparin, EDTA), cell lysate, and tissue. We want to select an ELISA kit that is compatible with your precious samples. If you’re unsure, contact support!
One of the most frustrating issues after performing an ELISA is when you realize that the strong signal obtained is actually a false positive result. Cross-reactivity has occurred. The antibodies have attached themselves to some other molecule instead of the target analyte.
On the other hand, interference happens when components in the sample matrix change antibody-antigen interaction, inhibiting the antibodies to find the target analyte.
How irritating, eh? We understand.
Boster’s PicokineTM ELISA kits have been optimized for minimal to no cross-reactivity and interference. We don’t just strive for high specificity, we require high specificity.
When looking at an ELISA kit’s specifications, remember to check for any cross-reactivity information provided by the manufacturer.
Do you have a general idea about the concentration of the target analyte in your sample?
If you have no clue about the concentration, it might be wise to choose an ELISA kit with a broad detection range.
If you know your samples contain extremely low levels of the target analyte, you need ELISA kits with high sensitivity for detection (such as Boster’s PicokineTM ELISA kits).
Our ELISA kits are empowered by our proprietary coating and blocking technology to achieve picogram-level sensitivity, high signal, and minimal background. Many of our ELISA kits are sensitive enough to detect as low as single-digit picogram limits!
Always be sure of the sensitivity and assay range before you purchase an ELISA kit. Remember, the more sensitive the kit is, the lower the working range will be.
Quality Antibody Pairs
If you’re considering sandwich ELISA, the pre-coated ELISA kit will utilize a matched antibody pair, in which the capture and detection antibody will each bind to a different, non-overlapping epitope of the antigen molecule.
It is typically better to have polyclonal and monoclonal antibody pairs, which prevents competition for the same binding site on an antigen.
Superior quality sandwich ELISA kits will have undergone extensive testing to select the optimal antibody pair for analyte detection. Suppliers should provide information about the antibody pairs included in their ELISA kits.
Reproducibility is key to credible science.
Achieving reproducibility with ELISA requires well-to-well and lot-to-lot consistency.
To obtain consistency, ELISAs must be subjected to rigorous validation and demonstrate precision.
Evaluate the precision of an ELISA kit by taking note of the coefficient of variation (CV) values for inter- and intra-assay precision. CV values must be below 10%.
Furthermore, access the datasheets and respective certificate of analysis (COA) for data on the standard curve and optical density (OD) values.
Together, these data help assess whether the ELISA kit will perform consistently and generate reproducible quality results that allow sample data to be comparable over time.
At Boster, we thoroughly test and diligently document the inter- and intra-assay variabilities for each batch of ELISA kits. We transparently share our validation data for your evaluation. You can even contact us for a detailed write-up of our validation procedures.
With more than 25 years of experience and 23,000 citations, Boster is proud to offer over 1,000 ready-to-use PicoKineTM sandwich ELISA kits that guarantee high sensitivity, specificity, and stability so that you can perform successful experiments and get better results with Boster.
Finally, Economical Choice
Your time and investment is important.
Quality is one of the main factors to consider when choosing an ELISA kit. Budget is another decisive one. However, please also be aware of the number of tests the kit provides and the amount of sample the kit requires to conduct the assay. Boster Bio’s ready-to-use PicokineTM ELISA kits are provided in 96-well format with removable strips, so you can use a portion now and store the rest for later!
Other than our PicoKineTM ELISA kits, Boster Bio also offers EZ SetTM ELISA kits (antibody pairs) for value-conscious customers who are experienced ELISA users. The EZ SetTM ELISA kit is an ideal low cost ELISA solution that contains DIY ELISA-optimized matched antibody pairs and other necessary core reagents to develop and run the ELISA.
What are you waiting for? Enter your target protein in the search bar on top and find your Boster ELISA kit today!
Questions? Contact [email protected] and we will be happy to assist you.