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- Table of Contents
DDX21 · Western blot design guide
DDX21 Western Blot Planning Guide
Plan a DDX21 Western blot around the catalog-observed 61.6 kDa band, image-backed A04605-2 evidence, HPA controls, and verified protocol records.
Evidence assembled July 2026 · For research use; verify linked source records and product datasheet before use
DDX21 Western Blot Experimental Design Guide
Expected bands, documented protocol parameters, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before running
| Expected band | 61.6 kDa | |
| Observed band | Not reported — verify product WB image | |
| Gel | 12-15% | |
| Positive control | Colon | |
| Negative control | Soft tissue |
Important caveats
Reasons your observed band may differ from the expected size.
| ⓘ | Calculated mass | 61.6 kDa |
| ⓘ | Localization | Nucleus, nucleolus |
| ⓘ | Processing / PTM | Record-dependent |
| ⓘ | Reactivity | Human |
Section 1
Real Curated DDX21 Western Blot Protocols
Start with the molecular-weight rule, then compare verified publication-derived conditions.
| Sample / lysate | Appendix |
| Gel % | 12-15% |
| Load | 20-30 µg total protein per lane |
| Transfer | Semi-dry, standard transfer |
| Membrane | 0.45 µm PVDF |
| Blocking | 5% non-fat milk or 5% BSA in TBST |
| Primary | A04605-2 at datasheet starting dilution |
| Primary incubation | Overnight at 4 °C with gentle agitation |
| Secondary | Species-matched HRP conjugate at validated dilution |
| Wash | 3 × 5 min in TBST |
| Detection | Chemiluminescent substrate |
| Exposure | Bracket exposures to avoid saturation |
Section 2
What Is the Expected DDX21 Western Blot Band Size?
Use the product-observed 61.6 kDa band as the primary planning value and retain the UniProt calculated mass as context.
| 61.6 kDa | Matches the authoritative product WB observation. |
| 61.6 kDa calculated | Use as UniProt context, not as a replacement observed band. |
| Unexpected additional signal | Do not assign identity without orthogonal positive/negative controls. |
💡Expected DDX21 appearancePlan around 61.6 kDa and keep the calculated mass as supporting context.
| Catalog-observed band | 61.6 kDa; use this as the primary experimental expectation. |
| Calculated mass | 61.6 kDa from UniProt Q9NY93; retain as context. |
| Gel selection | 12-15%; shared with the recommended protocol and poster. |
| Specificity check | Compare the lead HPA positive and negative controls with A04605-2. |
| Situation | Likely cause | Next action |
|---|---|---|
| 61.6 kDa | Matches the authoritative product WB observation. | Confirm with orthogonal controls and the linked product record. |
| Additional band | May reflect processing, modification, or non-specific signal. | Run a dilution series and compare positive/negative controls. |
| Weak signal | Target abundance or transfer may be limiting. | Verify transfer, increase positive-control abundance, and bracket exposure. |
Experiment evidence
Western blot images showing DDX21 band
A04605-2 · DDX21
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for DDX21 Western blot
🧪Use Colon as the first positive-control candidate and Soft tissue as the HPA Not detected negative candidate.
Positive control: Colon (High)
Negative control: Soft tissue (Not detected)
HPA protein score determines control status; other expression data is supporting context only.
HPA tissue expression evidence for DDX21
Comprehensive Human Protein Atlas IHC scoring per tissue. Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Colon | Reported tissue cells | High | Protein (HPA) | HPA → |
| Appendix | Reported tissue cells | High | Protein (HPA) | HPA → |
| Bone marrow | Reported tissue cells | High | Protein (HPA) | HPA → |
| Duodenum | Reported tissue cells | High | Protein (HPA) | HPA → |
Section 3
Advanced DDX21 Western Blot Tips
Deeper troubleshooting and optimisation questions for DDX21, answered from its protein features.
Which band should guide the blot?
Use 61.6 kDa, the observation attached to the authoritative A04605-2 WB record.
How should calculated mass be interpreted?
Treat the UniProt calculated mass as context; it does not replace the catalog-observed 61.6 kDa expectation.
Which positive control should I start with?
Start with Colon, the lead HPA protein-expression candidate.
Which negative control is defensible?
Use Soft tissue as an orthogonal HPA Not detected candidate.
Which gel should I use?
Use 12-15% consistently across the quick facts, protocol table, and poster.
What transfer method to use for DDX21 Western blot?
Use the transfer method in the recommended protocol and verify transfer before blocking.
How should A04605-2 be started?
Start at the linked datasheet condition and run a three-point primary-antibody dilution test.
Which publication-derived protocols can I compare?
No verified publication protocol was supplied; use only the deterministic recommended protocol.
Boster reagents
DDX21 Western Blot Reagents
Human-reactive DDX21 Western blot reagents with authoritative product imagery.
Real WB data
Anti-DDX21 Antibody Picoband®
Cat # A04605-2
Only image-backed, WB-validated Human/Mouse/Rat recommendations from the prepared catalog evidence are shown.
Source: prepared picoband-wb product evidence; each card retains its own SKU, URL, observed band, and authoritative WB image.
References
- UniProt Q9NY93
- Human Protein Atlas — DDX21
- A04605-2 product record
- PMC13284300 — Ubiquitination of DDX21 by HERC2 induces a dormancy-like phenotype via the NUCKS1-p21/p27 axis to promote radio-resistance in colorectal cancer cells (Cell death & disease, 2026)
- PMC6754283 — Activation of PARP-1 by snoRNAs Controls Ribosome Biogenesis and Cell Growth via the RNA Helicase DDX21 (Molecular cell, 2019)
- PMC10877017 — DEAD-box RNA helicase 21 interacts with porcine circovirus type 2 Cap protein and facilitates viral replication (Frontiers in microbiology, 2024)
