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- Table of Contents
CD74 · Western blot design guide
CD74 Western Blot Planning Guide
Plan a CD74 Western blot around the catalog-observed 33.5 kDa band, image-backed A01340-4 evidence, HPA controls, and verified protocol records.
Evidence assembled July 2026 · For research use; verify linked source records and product datasheet before use
CD74 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 | 33.5 kDa | |
| Observed band | Not reported — verify product WB image | |
| Gel | 12-15% | |
| Positive control | Skin | |
| Negative control | Epididymis |
Important caveats
Reasons your observed band may differ from the expected size.
| ⓘ | Calculated mass | 33.5 kDa |
| ⓘ | Localization | Cell membrane / Endoplasmic reticulum membrane |
| ⓘ | Processing / PTM | Record-dependent |
| ⓘ | Reactivity | Human |
Section 1
Real Curated CD74 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 | A01340-4 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 CD74 Western Blot Band Size?
Use the product-observed 33.5 kDa band as the primary planning value and retain the UniProt calculated mass as context.
| 33.5 kDa | Matches the authoritative product WB observation. |
| 33.5 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 CD74 appearancePlan around 33.5 kDa and keep the calculated mass as supporting context.
| Catalog-observed band | 33.5 kDa; use this as the primary experimental expectation. |
| Calculated mass | 33.5 kDa from UniProt P04233; 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 A01340-4. |
| Situation | Likely cause | Next action |
|---|---|---|
| 33.5 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 CD74 band
A01340-4 · CD74
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for CD74 Western blot
🧪Use Skin as the first positive-control candidate and Epididymis as the HPA Not detected negative candidate.
Positive control: Skin (High)
Negative control: Epididymis (Not detected)
HPA protein score determines control status; other expression data is supporting context only.
HPA tissue expression evidence for CD74
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 |
|---|---|---|---|---|
| Skin | Reported tissue cells | High | Protein (HPA) | HPA → |
| Cerebellum | Reported tissue cells | High | Protein (HPA) | HPA → |
| Appendix | Reported tissue cells | High | Protein (HPA) | HPA → |
| Duodenum | Reported tissue cells | High | Protein (HPA) | HPA → |
Section 3
Advanced CD74 Western Blot Tips
Deeper troubleshooting and optimisation questions for CD74, answered from its protein features.
Which band should guide the blot?
Use 33.5 kDa, the observation attached to the authoritative A01340-4 WB record.
How should calculated mass be interpreted?
Treat the UniProt calculated mass as context; it does not replace the catalog-observed 33.5 kDa expectation.
Which positive control should I start with?
Start with Skin, the lead HPA protein-expression candidate.
Which negative control is defensible?
Use Epididymis 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 CD74 Western blot?
Use the transfer method in the recommended protocol and verify transfer before blocking.
How should A01340-4 be started?
Start at the linked datasheet condition and run a three-point primary-antibody dilution test.
Which publication-derived protocols can I compare?
Compare only the supplied target-verified records: PMC8429975, PMC11669987, PMC6436447.
Boster reagents
CD74 Western Blot Reagents
Human-reactive CD74 Western blot reagents with authoritative product imagery.
Real WB data
Anti-CD74 Antibody Picoband®
Cat # A01340-4
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 P04233
- Human Protein Atlas — CD74
- A01340-4 product record
- PMC8429975 — Identification of invariant chain CD74 as a functional receptor of tissue inhibitor of metalloproteinases-1 (TIMP-1).
- PMC11669987 — Exosomes derived from microRNA-540-3p overexpressing mesenchymal stem cells promote immune tolerance via the CD74/nuclear factor-kappaB pathway in cardiac allograft.
- PMC6436447 — Immunophenotyping of the cluster of differentiation 74, migration inhibitory factor, and cluster of differentiation 44 expression on human breast cancer-derived cell lines.