Dextramer® Controls – Best Practices in Research Call for the Best Controls in Experiments
Controls eliminate confounding factors, distinguish signal from background, and help troubleshoot protocols
Controls Are the Core of Every Experiment
Positive and negative controls are often an afterthought in the design of experiments. And yet, without them, results leave room for ambiguity. Only properly controlled experiments can concretely discriminate hypotheses.
Controls also help resolve technical issues in experiments:
Dextramer® Negative Controls help maximize signal-to-noise ratios and enable accurate monitoring of your positive cell population.
MHC I Dextramer® Negative Control staining allows to distinguish a MART-1-specific CD8+ T-cell population from background staining using flow cytometry.
Why Use Negative Controls?
MHC Dextramer® are powerful flow cytometry reagents that bind with high avidity to antigen-specific T cells. This is a result of multiple simultaneous interactions at the cell surface between peptide MHC monomers on the Dextramer® and TCRs that recognize them. However, weaker general protein-protein- and other interactions not directly related to antigen recognition result in background staining of cells with lower intensity.
Negative control Dextramer® reagents are commonly used to set the threshold between background and antigen specific staining to optimize the gating/sorting of positive cells.
The Importance of Allele-Specific Negative Controls
Background staining can be allele-specific, in some cases related to the strength of the peptide-independent interaction between the MHC on the Dextramer® and CD8 on the T cell surface. In addition, background staining can also be donor-dependent.
We therefore advise the use of allele-matched antigen presenting MHC Dextramer® and negative control Dextramer®. We also recommend evaluating the background in every donor sample included in an experiment.
Allele-Specific Negative Control Dextramer®
We have developed a new class of allele-specific negative control reagents based on a novel innovative design. We use peptide pools of enormous diversity to create MHC Dextramer® that differ fundamentally from our normal reagents.
Instead of presenting a single pMHC monomer, Allele-Specific Negative Control Dextramer® are decorated with MHC monomers that all present different peptides. In addition, no two Allele-Specific Negative Control Dextramer® molecules are likely to be composed of the same combination of pMHCs.
As a result, Allele-Specific Negative Control Dextramer® are unable to bind to T cells by antigen-specific TCR engagement. Thus, they are ideal for the delineation of background-stained cell populations.
Allele-Specific Negative Control Dextramer® Performance
Allele-Specific Negative Control Dextramer® were used to stain multiple allele matched donor samples, which were then analyzed by flow cytometry. Representative flow charts show the very limited background staining observed with these reagents.
In addition, allele-specific differences in background staining are appreciated by comparing the beak shaped populations of CD8+ T cells weakly stained with either HLA-A*01:01 or HLA-A*03:01 Allele-Specific Negative Control Dextramer® (upper left quadrant), with the more homogenously stained cell populations achieved with HLA-A*02:01 and HLA-B*07:02 Allele-Specific Negative Control Dextramer® reagents.
Order Dextramer® Controls
Couple your Dextramer® reagents with the right positive and negative controls. Immudex offers a range of Dextramer® Positive and Negative Controls including the new Allele-Specific Negative Control Dextramer® with fluorophore labelling (BV421, FITC, PE or APC) for your flow cytometry and immunohistochemistry experiments. Allele-Specific Negative Control Dextramer® are listed in the table below, and other Dextramer® Positive and Negative Controls can be found in the webshop at the bottom of this page.
You can use the webshop below to order online. Alternatively, send an email to [email protected] specifying:
Catalog number or desired MHC allele-peptide combination
Fluorophore (BV421, FITC, PE, APC, or none)
Test size (50,150, 500, 1000 tests). One test is 10 µl reagent and sufficient to stain 1–3 x 106 lymphoid cells or 1–3 x 105 clonal antigen-specific T cells
Catalog Number
Product Name/Description
Test Size
Dye
Price
WB05535
Allele-Specific Dextramer®, HLA-A*0201 / Neg. Control
50/150/500/1000 tests
APC/FITC/PE/None
EUR 1305 / 2440 / 5875 / 11150
USD 1540 / 2730 / 6625 / 12595
WB05535
Allele-Specific Dextramer®, HLA-A*0201 / Neg. Control
50/150/500/1000 tests
BV421
EUR 1785 / 3330 / 8000 / 15200
USD 2100 / 3730 / 9035 / 17180
WH05536
Allele-Specific Dextramer®, HLA-B*0702 / Neg. Control
50/150/500/1000 tests
APC/FITC/PE/None
EUR 1305 / 2440 / 5875 / 11150
USD 1540 / 2730 / 6625 / 12595
WH05536
Allele-Specific Dextramer®, HLA-B*0702 / Neg. Control
50/150/500/1000 tests
BV421
EUR 1785 / 3330 / 8000 / 15200
USD 2100 / 3730 / 9035 / 17180
WA06219
Allele-Specific Dextramer®, HLA-A*0101 / Neg. Control
50/150/500/1000 tests
APC/FITC/PE/None
EUR 1305 / 2440 / 5875 / 11150
USD 1540 / 2730 / 6625 / 12595
WA06219
Allele-Specific Dextramer®, HLA-A*0101 / Neg. Control
50/150/500/1000 tests
BV421
EUR 1785 / 3330 / 8000 / 15200
USD 2100 / 3730 / 9035 / 17180
WC06220
Allele-Specific Dextramer®, HLA-A*0301 / Neg. Control
50/150/500/1000 tests
APC/FITC/PE/None
EUR 1305 / 2440 / 5875 / 11150
USD 1540 / 2730 / 6625 / 12595
WC06220
Allele-Specific Dextramer®, HLA-A*0301 / Neg. Control
50/150/500/1000 tests
BV421
EUR 1785 / 3330 / 8000 / 15200
USD 2100 / 3730 / 9035 / 17180
Don’t find an Allele-Specific Negative Control Dextramer® for your desired allele? Please contact us and we will make it!
Dextramer® Controls
Depending on your experimental setup, you can select between Dextramer® Negative Controls with MHC monomers presenting:
a peptide pool (Allele-Specific Negative Control Dextramer®)
an empirically derived peptide sequence (MHC I) known to give very low levels of background staining
a peptide sequence unrelated to your experiment
a CLIP peptide (MHC II)
Depending on your experimental setup, you can order Dextramer® Positive Controls that:
recognize epitopes derived from widespread human viruses (CMV, EBV, and Flu)
carry three viral epitopes from CMV, EBV and Flu and are then pooled
*H2-Kb/SIYRYYGL (SIY) can be used as a positive and negative control depending on the mouse model. For example, in OVA mouse models, it can serve as a negative control reagent, while H-2KB/SIINFEKL is the positive control reagent [1,2].
*H2-Kb/SIYRYYGL (SIY) can be used as a positive and negative control depending on the mouse model. For example, this peptide is expressed in certain mouse models for tumors and recognized by CD8+ T cells expressing 2C TCR. Thus, it can be used as a positive control [4,5].
Can’t find what you’re looking for?
Our webshop does not include all products. Contact us or email [email protected] and we will search our larger internal database of products for you. We also provide custom alleles and specificities.
Don’t find a Allele-Specific Negative Control Dextramer® for your desired allele?Please contact us and we will make it!
For custom MHC-peptide combinations, a one-time entry fee will be required to evaluate each unique peptide's ability to bind to the requested MHC allele using standardized peptide binding assays. If the refolding process is unsuccessful, only the entry fee will be charged as we will not be able to deliver a product to you. The entry fee for custom MHC I Dextramer® reagents is 385 EUR / 445 USD and the entry fee for custom MHC II Dextramer® reagents is 605 EUR / 710 USD.
Dextramer® Custom Controls
Your experimental setup may require an MHC allele that is not listed in our catalog or different specificities. Our Custom Solutions and Services Team can ensure you have the right controls for your research. Just contact us.
BV421 is equivalent to Brilliant Violet™ 421, which is a trademark or registered trademark of Becton, Dickinson and Company or its affiliates, and is used under license. Powered by BD Innovation.
