January 25, 2016
By: Grace Ayabe, Technical Support
Would you like a positive control for production of cytokines in human peripheral blood mononuclear cells (PBMC’s)? If your laboratory is testing for cytokine production, List Labs can provide you with SEB (Staphylococcus aureus, Enterotoxin Type B) to stimulate a positive response to assure that your cells are functional.
SEB is described as a ‘superantigen’ for its ability to bind to Major Histocompatibility Complex (MHC) class II molecules on antigen presenting cells and specific vβ regions of T-cell receptors stimulating a large population of T-cells; which in turn, produce an inappropriate flood of cytokines or a ‘cytokine storm’. Following SEB exposure, human peripheral blood cells release large quantities of IL-2, IL-4, IL-6, TNF-A and INF-c. SEB has also been found to bind to another regulator of the T-cell immune response, CD28. You can read more about T-cell proliferation with List Labs SEB here: https://www.listlabs.com/blog/staphylococcus-enterotoxin-b-stimulates-t-cell-proliferation/
If your research utilizes an Enzyme-linked immunospot (ELISPOT) or cytokine flow cytometry (CFC)/intracellular cytokine staining (ICS) assay(s) for cytokine detection, List Labs provides a premium quality SEB (Staphylococcus aureus, Enterotoxin Type B; Product #122) for your use as a positive control.
Each vial of List Labs SEB (Staphylococcus aureus, Enterotoxin Type B; Product #122) contains 0.5 mg of SEB in 0.07 M Sodium Phosphate; pH 6.8 (lyophilized). For more information, visit: https://www.listlabs.com/products/buy-enterotoxin-type-b-from-staphylococcus-aureus
SEB is a ‘Select Agent’. To order SEB from List Labs for the first time, please review the following link: https://www.listlabs.com/controlled-substances/
Can you tell me the expiry of the SEB once it is reconstituted, aliquoted, and frozen as per manufacturer’s instruction?
Hi Jessica. Thanks for your inquiry. We typically don’t assign expiration dates to our products once reconstituted. However, SEB is highly stable and is stored frozen as bulk material. If you’d like to see the Certificate of Analysis, it is available online: https://www.listlabs.com/mediafiles/c_of_a/1224A1-932.pdf
If you have any further inquiries which are technical in nature, we also have an online Technical Support Portal. You can go to https://listlabsinc.desk.com/ and browse our Knowledge Base. Here, you can also submit a technical support ticket. Let us know if you need any assistance using this feature or if there is any other way we can assist you.
We hope this is helpful! Thank you again for using List Labs products in your studies. We wish you continued success with your research.
Dear List Labs team
Do you have any knowledge of the optimum stimulation protocol using SEB and assessment of cytokines release from cryopreserved PBMC. I have a good idea on the concentration range but wonder if you have any thoughts on whether the SEB is best used in a ‘pulsed’ manner, or left in the cultures for the entire incubation. Also is there a preferred stimulation window for the major inflammatory cytokines with SEB stimulation. We see a lot of within donor variation between repeat assays and are using SEB at final conc of 100 ng/mL for 3hrs – harvesting at 3, 6 and 9 hrs. Any suggestions would be very helpful.
Hello David – Thank you for your question. We do not perform research in our laboratory, so unfortunately, we are not equipped to answer this question, but please feel free to refer to our citations page to look for related research and applications https://www.listlabs.com/citations