Tag antibodies are essential reagents for detecting, purifying, and characterizing recombinant proteins in expression systems. Epitope tags — short peptide sequences or fusion proteins engineered onto the target protein — provide a universal detection handle that eliminates the need for target-specific antibodies during early-stage expression screening, purification validation, and protein interaction studies.
abinScience offers a comprehensive panel of tag antibodies covering all major epitope tags — His, Flag/DYKDDDDK, Strep-tag, HA, Myc, V5, GST, and MBP — in recombinant and monoclonal formats. Multiple conjugate options (unconjugated, HRP, FITC, PE, APC, biotin) enable direct detection across western blot, immunofluorescence, immunoprecipitation, ELISA, and flow cytometry workflows. For fluorescent protein tags, see our dedicated GFP & EGFP Detection Guide.
Common Protein Tags & Applications
| Tag Name |
Sequence / Size |
Primary Use |
Popular Assays |
| His-tag (6×His) |
HHHHHH (~1 kDa) |
Ni-NTA / IMAC purification |
WB, ELISA, IP |
| Flag-tag (DYKDDDDK) |
DYKDDDDK (1.0 kDa) |
Immunoaffinity purification, enterokinase-cleavable |
WB, IP, IF, FC |
| Strep-tag II |
WSHPQFEK (1.1 kDa) |
Strep-Tactin affinity purification under native conditions |
WB, ELISA |
| HA-tag |
YPYDVPDYA (1.1 kDa) |
Detection in transient expression & co-IP |
WB, IP, IF, IHC |
| Myc-tag |
EQKLISEEDL (1.2 kDa) |
Immunological detection & dual-tag strategies |
WB, IF, ELISA |
| V5-tag |
GKPIPNPLLGLD (1.4 kDa) |
Expression validation in mammalian & insect cells |
WB, IF, FC, ELISA |
| GST |
26 kDa fusion protein |
Glutathione affinity purification, solubility enhancement |
WB, ELISA, pull-down |
| MBP |
42.5 kDa fusion protein |
Amylose purification, solubility enhancement in E. coli |
WB, ELISA |
How to Choose the Right Tag Antibody
| Your Application |
Recommended Format |
Why |
| Western blot (direct detection) |
HRP-conjugated anti-tag |
Skip secondary antibody step; faster protocol |
| Flow cytometry |
FITC / PE / APC-conjugated anti-tag |
Direct staining in multi-color panels |
| Co-immunoprecipitation |
Unconjugated anti-tag + Protein A/G beads |
Flexible bead coupling; high capture efficiency |
| Dual-tag experiments |
Two antibodies from different host species |
Avoid cross-reactivity between detection channels |
| ELISA / sandwich assay development |
Matched pair: unconjugated (capture) + HRP (detection) |
Optimized pairing for quantitative detection |
Why Choose abinScience Tag Antibodies?
✓ High specificity & low cross-reactivity — minimal background in endogenous protein detection
✓ Validated across applications — WB, IF, IP, ELISA, flow cytometry
✓ Multiple conjugates — unconjugated, HRP, FITC, PE, APC, PerCP, biotin for flexible assay design
✓ Recombinant production — lot-to-lot consistency with defined sequence and low endotoxin
Flag Tag (DYKDDDDK): A Closer Look
The Flag tag is an eight-amino-acid peptide (DYKDDDDK, ~1.0 kDa) designed specifically for immunoaffinity purification and immunodetection of recombinant proteins. Unlike naturally derived tags such as His or GST, the Flag sequence was engineered de novo to be highly antigenic, hydrophilic, and non-interfering with protein folding — which is why it remains one of the most popular epitope tags in molecular biology research.
Flag vs 3×Flag: When to Use Which
The standard Flag tag is a single DYKDDDDK sequence. The 3×Flag (triple-Flag) tag consists of three tandem DYKDDDDK repeats separated by short linkers, producing a total peptide of ~2.7 kDa. The practical differences:
| |
Flag (1×) |
3×Flag |
| Detection sensitivity |
Standard |
~10× higher — three epitopes per molecule means more antibody binding sites, stronger WB signal |
| Best for |
Abundant proteins; applications where tag size matters |
Low-abundance proteins; ChIP, Co-IP, and other pulldown applications where sensitivity is critical |
| Tag removal |
Enterokinase cleaves after the DYKDDDDK sequence (requires C-terminal positioning) |
Same enterokinase site available; some 3×Flag vectors also include TEV or PreScission sites |
| Antibody compatibility |
Anti-Flag M2 clone recognizes both |
Anti-Flag M2 clone recognizes both (all three epitopes accessible) |
Anti-Flag Tag Antibodies
The M2 clone is the industry standard anti-Flag antibody — it recognizes the DYKDDDDK sequence regardless of whether the tag is at the N-terminus, C-terminus, or internal position, and works with both Flag and 3×Flag constructs. abinScience offers M2 in multiple formats:
| Product Name |
Catalog No. |
Clone |
Format |
Applications |
| Anti-Flag Tag (DYKDDDDK) Recombinant Antibody |
YP666013 |
M2 |
Unconjugated |
ChIP, ELISA, FCM, WB, IP, ICC, IF |
| Anti-Flag Tag (DYKDDDDK) Recombinant Antibody, HRP |
YP666913 |
M2 |
HRP-conjugated |
ChIP, ELISA, FCM, WB, IP, ICC, IF |
| Anti-Flag Tag (DYKDDDDK) Recombinant Antibody |
YP666023 |
2H8 |
Unconjugated |
ChIP, IF, IP, WB |
| Flag Tag Control Recombinant Protein (C-terminal) |
YP428012 |
— |
Protein |
SDS-PAGE, WB, ELISA, Immunogen |
Tip: For Co-IP experiments using Flag-tagged bait proteins, use the unconjugated M2 antibody (YP666013) with Protein A/G beads. The M2 clone has high IP capture efficiency and works with both native and crosslinked complexes. For direct WB detection without secondary antibody, use the HRP-conjugated M2 (YP666913).
Frequently Asked Questions
What is the difference between Flag-tag and DYKDDDDK-tag antibodies?
They are the same. DYKDDDDK is the amino acid sequence of the Flag-tag peptide. Some suppliers use "anti-DYKDDDDK" to avoid trademark issues associated with the "FLAG" name. abinScience anti-Flag antibodies recognize the DYKDDDDK epitope and are functionally identical regardless of naming convention.
Which tag should I use for my recombinant protein?
The choice depends on your downstream application. His-tag is the most universal choice for IMAC purification. Flag-tag is ideal when you need protease-cleavable tag removal (enterokinase site). Strep-tag II offers the gentlest purification conditions (native elution with desthiobiotin). For solubility-challenged proteins expressed in E. coli, GST or MBP fusion tags can significantly improve folding and yield. For fluorescent protein tags, see our GFP & EGFP guide.
Can I use the same anti-tag antibody for both western blot and flow cytometry?
The same clone can work for both, but you may need different conjugate formats. Use an HRP-conjugated version for western blot and a fluorochrome-conjugated version (FITC, PE, or APC) for flow cytometry. Unconjugated antibodies work for both when paired with an appropriate secondary antibody.
Do you offer anti-Twin-Strep-tag antibodies?
Yes. We offer a recombinant anti-Twin-Strep-tag antibody (clone SAA0348) that specifically recognizes the tandem Twin-Strep-tag format. Browse our Strep Tag antibody selection, or contact us for clone recommendations.
All products are for research use only (RUO). Not intended for diagnostic or therapeutic use.
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