Enzyme-Linked Immunosorbent Assay (ELISA) Kits Frequently Asked Questions

How many ELISA kits do we offer?

We offer >1000 ELISA Kits. Please see the break down below.


What is provided in the kit?

Kits include everything needed to run the experiment.


I see that these kits are included in the Bioguarantee Program – what exactly does that mean?

We invite researchers to evaluate our antibody products, including our ELISA kits, with complete peace of mind. If our antibody does not perform in their application of interest or species specificity – no matter what – we will issue a full credit or replacement antibody product – Bioguaranteed.

How it works:

  1. Place antibody or ELISA kit order online or call 800-325-3010.
  2. Following the researchers evaluation, if they are not completely satisfied with the performance of the ELISA kit, complete our Bioguarantee Form that can be found at sigma.com/bioguarantee
  3. Our technical service team will contact you within 24-48 hours to review the details of your experiment and complete your claim*.


The kit got left out at room temperature for several days. Is it still good?

The most temperature-sensitive components in the kit are the HRP-streptavidin and the detection antibody. These may have lost some activity, but the kit is probably still usable.


What is the stability & storage of the kit components?


What is the recommended sample dilution?

Based on our sample testing studies, we have established dilution factors for serum & plasma (all species).  General recommendations for sample dilution is provided in the tech bulletin or in  the Certificate of Analysis, but optimal sample dilution must be determined by the researcher.

NOTE: the lowest dilution we ever recommend for serum/plasma is 2-fold.

Our recommended dilutions are meant to be a starting point ONLY.  Optimal dilutions may vary from sample to sample.

For cell culture media, the optimal dilution factors must be determined empirically by the user.  We suggest starting with neat to 2-fold.


Does this kit detect unusual species? e.g. dog, ferret, rabbit, horse, elephant, opossum?

For exotic (i.e. not human, mouse or rat) species, it’s most likely unknown. But check with us anyway, as we may have some helpful information about the antigen or other cross-reactive species.

We do offer a selection of kits for canine, feline, porcine, rhesus, equine, sigmodon and bovine testing.


My customer uses another vendor’s kit previous and just used ours and received different results? Why were the results different?

  • ELISA kits from different manufacturers are very likely to give different results
  • Differences in the properties of the antibody or standard, the calibration, optimization conditions, and other factors contribute to this
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