Labelled Proteins
Labelled proteins in this range are recombinant human and cross-reactive antigens carrying a biotin label, produced predominantly in HEK293 cells and supplied with a His-Avi, His, or Fc capture tag alongside the biotin. The biotin label allows the protein to be captured on streptavidin-coated surfaces for solid-phase binding assays, without a separate conjugation step.
Browse Labelled ProteinsBiotinylation for Solid-Phase Binding Assays
Each protein in this range is produced with a purification tag (His, His-Avi or Fc) alongside a site-specific or chemical biotin label. The His-Avi format uses the BirA enzyme recognition sequence, giving a single biotin per protein and a defined orientation on a streptavidin surface, which matters for assays such as surface plasmon resonance or bio-layer interferometry where uniform ligand presentation affects the binding signal. Purity for each protein is confirmed by Tris-Bis PAGE under reducing conditions, with the gel image supplied on the product datasheet, and select targets additionally report SEC-HPLC purity or a functional ELISA binding curve.
| Tag Format | Typical Use | Example Targets in This Range |
|---|---|---|
| His-Avi / N-His-Avi | Site-specific biotinylation, defined orientation on streptavidin surfaces (SPR, BLI) | BTLA, CD161, AXL, BAFFR, BAFF/TNFSF13B/CD257 Trimer |
| His-Tag (non-Avi) | General-purpose capture, ELISA and variant comparison work | COV2 Spike Protein RBD, S and S1 (B.1.1.529 Omicron) |
| hFc-Avi | Bivalent Fc presentation alongside site-specific biotin | Human 4-1BB/TNFRSF9 |
Two Targets With Functional Binding Data
The biotinylated SARS-CoV-2 Spike S1 protein and BCMA were chosen for the specific binding or disease relevance documented on their own product pages, beyond the standard purity gel supplied across the range.
2019 nCoV/COVID-19 Spike Protein S1 (Biotin) (STJP000266)
The SARS-CoV-2 spike receptor-binding domain engages the ACE2 receptor through an interface of around 850 Ų involving 18 direct-contact residues.1 This HEK293-expressed, biotinylated Spike S1 protein was coated at 0.1 µg per well and bound to human ACE2-Fc, with an EC50 of 35 ng/ml, confirming functional receptor engagement rather than purity alone.
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Human BCMA/TNFRSF17 Protein (C-His-Avi) (Biotin) (STJP001691)
BCMA (CD269, TNFRSF17) is a plasma cell surface receptor that binds BAFF and APRIL to support plasma cell survival, and is consistently and selectively expressed on malignant plasma cells in multiple myeloma, making it a leading CAR-T and antibody-drug conjugate target.2 This His-Avi biotinylated format supports streptavidin-based binding and potency assays for anti-BCMA antibody or CAR-T screening.
View product →Labelled Proteins for Immune Checkpoint Research
Biotinylated B7 family and coinhibitory receptors for streptavidin-based checkpoint binding assays. The range covers B7-1 (CD80) and B7-2 (CD86), the two ligands that engage CD28 to costimulate or CTLA-4 to inhibit T cell activation, B7-H4, a coinhibitory B7 family ligand studied in tumour immune evasion, and BTLA, an inhibitory receptor structurally related to PD-1 that limits lymphocyte activation. Each is supplied His-Avi biotinylated for defined-orientation capture on a streptavidin surface.
Labelled Proteins for TNF Superfamily and Costimulation Research
Biotinylated TNF receptor and ligand superfamily members used in B cell survival and T cell costimulation research. 4-1BB (TNFRSF9) is an inducible costimulatory receptor on activated T cells, BAFF (TNFSF13B) and its receptor BAFFR (TNFRSF13C) form a B cell survival signalling axis, BCMA (TNFRSF17) is the plasma cell receptor central to current myeloma immunotherapy, and CD30 (TNFRSF8) is a TNF receptor superfamily member expressed on activated lymphocytes and used as a diagnostic and therapeutic target in lymphoma. The BAFF and BCMA trimeric formats reflect the native ligand oligomerisation state relevant to receptor engagement.
Labelled Proteins for Tumour and NK Cell Marker Research
Biotinylated markers spanning tumour-associated antigens, adhesion molecules and NK cell receptors. ALCAM (CD166) is a cell adhesion molecule used in tumour invasion research, AXL is a receptor tyrosine kinase studied in tumour immune evasion and drug resistance, CA125 (MUC16) is a mucin used as the principal serum biomarker in ovarian cancer research, and CD161 is a C-type lectin receptor expressed on NK cells and a subset of T cells. All four are supplied His-Avi biotinylated for streptavidin-based capture.
Labelled Proteins for SARS-CoV-2 Variant Research
Biotinylated spike and receptor-binding domain constructs for the original 2019-nCoV sequence and the B.1.1.529 (Omicron) variant, which carries 15 mutations in the receptor-binding domain that drive escape from RBD-targeted neutralizing antibodies.3 Parallel biotinylated constructs across the original sequence and Omicron support side-by-side ELISA and SPR comparison of ACE2 binding and antibody recognition between variants.
Looking for a Specific Labelled Target?
Browse the full range of biotinylated recombinant proteins, or contact us if a specific target or tag format is not listed.
Browse Labelled Proteins1. Lan J, Ge J, Yu J, et al. Structure of the SARS-CoV-2 spike receptor-binding domain bound to the ACE2 receptor. Nature. 2020;581(7807):215-220.
2. Carpenter RO, Evbuomwan MO, Pittaluga S, et al. B-cell maturation antigen is a promising target for adoptive T-cell therapy of multiple myeloma. Clin Cancer Res. 2013;19(8):2048-2060.
3. Cao Y, Wang J, Jian F, et al. Omicron escapes the majority of existing SARS-CoV-2 neutralizing antibodies. Nature. 2022;602(7898):657-663.