HLA-DRA1*01:01(HLA-DRB1*01:01)(PKYVKQNTLKLAT) Class II Tetramer
HLA-DRA1*01:01 PKYVKQNTLKLAT Class II Tetramer Developed and Manufactured by immunAware
Size: 50, 150, or 500 tests
Organism: Influenza A virus
Epitope: HA 306-318 (IEDB#: 48237)
HLA: Recombinant HLA-DRA1*01:01 / recombinant HLA-DRB1*01:01 with a C-terminal biotinylation. HLA-DRB1*01:01, the unpaired Cysteine in position 30 is substituted with Serine.
Formulations: peptide-HLA-I monomer, biotinylated
peptide-HLA-II tetramer with PE or APC label
Buffer: PBS pH 7.4 containing 5% Glycerol
For Research Use Only
The HLA-DRA1*01:01 PKYVKQNTLKLAT Class II Tetramer can be used in flow cytometric analysis to characterise and quantify epitope specific CD4+T cells.
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Please note that the staining intensity can vary between tetramer specificities, hence the tetramer concentration should be titrated the first time a specific tetramer is used. Note, it may be an advantage to stain for the same tetramer specificity with two different fluorochrome labels. It gives a more accurate definition of the tetramer positive population. Often antigen specific CD4+ T cells are of very low frequency and can be difficult to detect directly ex vivo. A prior enrichment or short 7-day in vitro stimulation is recommended for such detection.
Materials and equipment
- Fluorophore-labeled HLA class II tetramer(s)
- Fluorophore-labeled antibodies against phenotypic markers (CD3, CD4, and other optional markers)
- 96-well U-bottom plate
- FACS buffer: PBS with 1%BSA (or FCS) and 0.1% NaN3.
- Centrifuge with a plate rotor
- Flow cytometer
A tetramer assay (tetramer stain) is used to detect and quantify antigen specific T cells. The interaction between a peptide MHC complex (pMHC) and a cognate T cell receptor (TcR) is of too low affinity to be detected in flow cytometry. Multimerization of monomeric biotinylated pMHC by streptavidin (1) complexing increases the avidity of the pMHC streptavidin tetramer towards cognate TcRs to allow detection of antigen specific T cells.