FAQ

Why Tetramers

Q: Why should I use MHC Tetramers?

A: Because MHC Tetramers is the only reagent for precise monitoring and enumeration of CD8+ antigen-specific T cells in fluid samples of lymphoid cells (PBMCs, TILs, or splenocytes).

 

Q: How are Tetramers used?

A: MHC Tetramers are used for staining antigen-specific T cells in samples of lymphoid cells (PBMCs, TILs, or splenocytes). After staining T cells are detected by flow cytometry. Please see our protocol.

Ordering.

Q: How do I order?

A: You can order

 

Payment

Q; How do I pay?

A: You can pay by credit card.

A: You can pay by bank transfer

  • Name of bank: Danske Bank
  • IBAN: DK4030000012754671
  • SWIFT: DABADKKK

 

A: Payment shall be made in cash no later than 15 days from date of invoice. See Terms & Conditions.

 

Shipment

Q: What is the delivery time?

A: Empty Loadable Tetramers ship within two days of receiving your order.

A: Off-the-shelf Tetramers ship within two days of receiving your order.

A: Customer-defined Tetramers ship two days after receiving your custom peptide. Normally this is within 3 weeks of receiving your order.

 

Q: Do I need to provide Tetramer Shop with any special documents to be able to purchase tetramers?

A: In some countries, you may need an Import Permit to be able to have the tetramers cleared in customs (e.g. Australia and New Zealand).

 

Distributors

Q: Do you have distributors?

A: No. To keep cost of Tetramers low Tetramer Shop sell and ship MHC Tetramers directly to all countries through web-based sale/online sale.

A: If you would like to distribute our products you are welcome. However, the same pricing and discounts apply as for ordinary customers.

MHC Tetramer Product

Q: What is the formulation and concentration of the Tetramer?

A: Our Tetramers are sold as test quantities in PBS, pH 7.4 containing, 0,5% BSA, 5% glycerol and <0.01% NaN3. One test is 5 µl. A 50 test size contains 250 µL MHC Tetramer reagent. One test contains 0.2 µg MHC monomer conjugated to 0.05 µg streptavidin with relevant fluorochrome.

 

Q: What are your different lines of Tetramer?

A: We offer three product lines of Tetramers

  1. Off-the-shelf  Tetramers: These are ready-made Tetramers displaying common peptide antigens. Shipping within 48 hours from ordering.
  2. Custom Tetramers: These are custom-made Tetramers displaying a peptide antigen defined by the customer. Since the peptide needs to be synthetized these reagents can only be shipped approximately 4 weeks from ordering.
  3. Empty Loadable Tetramers: These are Tetramers empty of peptide antigen ready to accept peptide. Essentially these Empty Loadable Tetramers represent DIY Tetramers or Tetramers on demand. Empty Loadable Tetramers offer unprecedented antigen-flexibility and can dramatically reduce Tetramer expenses for the customer.

 

Q: Can you provide a NaN3 free product?

A: Yes. Please enquire by mail to ordering@tetramer-shop.com

 

Q: Can Tetramer Shop provide me with peptides?

A: Yes, we can provide you with peptides. We charge €50/$60 for 40µg. Enough for loading 200 tests of MHC Tetramers with peptide antigen.

Please check “Peptide – Scroll Down” for available peptides ready for shipping.

 

Q: What is the minimum recommended affinity for peptides to generate functional MHC Tetramers?

A: We produce MHC Tetramers through a proprietary technology providing stabilized, empty MHC monomers. The higher the affinity of the peptide for the MHC complex the higher chance of having peptide presentation in the context of MHC and thus functional MHC Tetramers. We use the prediction tool NetMHC to predict the theoretical affinity between the peptide and the allele of choice. http://www.cbs.dtu.dk/services/NetMHC/

 

Q: How do you purify and quality control your MHC Tetramers?

A: Due to our proprietary production technology, we are able to produce large batches of antigen-empty MHC monomer and test each batch with several peptide antigens before release for sale. All products are produced to the highest quality with little lot-to-lot variation and are quality controlled (QC). We perform several QC tests on the Tetramer lots before shipment. We QC for correct folding of the MHC complex using several common virus peptides and subsequent staining of donor material and analysis by flow cytometry.

 

Why Empty Loadable Tetramers and what is it for?

Q: Can you provide empty MHC Tetramers?

A: Yes, we can. This is a paradigm shift in MHC Tetramer production and offers a huge advantage to T cell immunology research since large peptide libraries can now be screened efficiently at low cost. Conventional MHC I molecules without a peptide are extremely unstable. It has therefore not previously been possible to produce and sell MHC Tetramers/multimers with empty MHC molecules.

 

Our proprietary production technology allows for the production of empty, stable MHC Tetramers that can be instantly loaded with peptide antigen. Simply just ad dissolved peptide to your empty/loadable MHC Tetramer, incubate and stain your cells. Check out our standard protocols.
No UV-cleavage, no bleaching, no chaotropic salts, no heating, no peptide exchange. Just ad peptide and stain.

 

Q: Why are your Empty Loadable MHC Tetramers stable?

A: Production of our proprietary MHC monomers is based on introduction of an extra disulfide bond in the heavy chain of the MHC monomer which provides antigen-independent folding and stability of the MHC complex. Check out our Technology.

 

Q: Is your MHC production technology based on UV-induced peptide exchange, heating or chaotropic salts?

A: No, we do not use UV-exchange, heating or chaotropic salts. Just Empty Loadable Tetramers ready to accept peptide antigen.

 

Q: Why do your Tetramers stain brighter than conventional tetramers/multimers?

A: This has not been fully investigated. We believe that our stabilized MHC monomers does not fall apart when the peptide leaves the binding pocket of the MHC complex. This is certainly the situation for conventional MHC monomers where the MHC monomer will fall apart until the equilibrium between free peptide and MHC complex is reached at [free peptide] = Kd(peptide:MHC). The effect is that our MHC tetramers are true MHC tetramers whereas conventional tetramers/multimers slowly disintegrate due to peptide loss.

 

Q: What can Empty Loadable Tetramers be used for?

A: Empty Loadable Tetramers can be used just like conventional Tetramers. However, they are supplied empty of peptide antigen and you have to add peptide before you can stain your T cells. Check out our protocols.

 

Q: What is the advantage of Empty Loadable Tetramers?

A: Besides the improved stability and brighter staining, the major advantage is that you can instantly (30 min loading protocol but in practice < 1 min) DIY your own Tetramer specificities. This is a dramatic increase in flexibility of Tetramer assays and can save your Tetramer expenses significantly. This is in particular advantageous when you are staining

  • for multiple T cell specificities;
  • for reactivity against neoantigens; or
  • for proprietary peptide antigens that you do not wish to disclose.

 

Pricing and discounts

Q: Why are your tetramers cheaper than competing products?

A: The proprietary production technology allow us to produce large batches of QC’ed, empty MHC monomers and diversify these with peptide antigens upon specific orders. This is opposed to conventional production of MHC tetramers/multimers where small batches of specific orders are produced and QC’ed individually. Furthermore, we pursue online sale, which also keep our cost structure low. This allows us to sell our products at lower cost.

 

Q: Do you offer discounts?

A: Yes, but to be fair everyone gets the same discount. No secret deals. If you purchase 150 tests you get approximately 25% discount compared to purchasing 3×50 test size. If you purchase a 500 test you get approximately 50% discount over purchasing 10×50 tests. If you purchase four items, you get 25% discount on the whole order. If you purchase ten or more items, you get 40% discount overall.

Licensing

Q: Do you give license to your proprietary technology for stable MHC molecules?

A: Yes. Please contact snj@tetramer-shop.com

Protocols

Q: Where can I find protocols for use of your products?

A: Please see our list of protocols »».