This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
CFI · Western blot design guide
CFI Western Blot Planning Guide
Plan a CFI Western blot around the catalog-observed 65.8 kDa band, image-backed PB9935 evidence, HPA controls, and verified protocol records.
Evidence assembled July 2026 · For research use; verify linked source records and product datasheet before use
CFI 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 | 65.8 kDa | |
| Observed band | Not reported — verify product WB image | |
| Gel | 12-15% | |
| Positive control | Testis | |
| Negative control | Appendix |
Important caveats
Reasons your observed band may differ from the expected size.
| ⓘ | Calculated mass | 65.8 kDa |
| ⓘ | Localization | Secreted, extracellular space / Secreted |
| ⓘ | Processing / PTM | Record-dependent |
| ⓘ | Reactivity | Human / Rat |
Section 1
Real Curated CFI Western Blot Protocols
Start with the molecular-weight rule, then compare verified publication-derived conditions.
| Sample / lysate | Testis |
| 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 | PB9935 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 CFI Western Blot Band Size?
Use the product-observed 65.8 kDa band as the primary planning value and retain the UniProt calculated mass as context.
| 65.8 kDa | Matches the authoritative product WB observation. |
| 65.8 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 CFI appearancePlan around 65.8 kDa and keep the calculated mass as supporting context.
| Catalog-observed band | 65.8 kDa; use this as the primary experimental expectation. |
| Calculated mass | 65.8 kDa from UniProt P05156; 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 PB9935. |
| Situation | Likely cause | Next action |
|---|---|---|
| 65.8 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 CFI band
PB9935 · CFI
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for CFI Western blot
🧪Use Testis as the first positive-control candidate and Appendix as the HPA Not detected negative candidate.
Positive control: Testis (High)
Negative control: Appendix (Not detected)
HPA protein score determines control status; other expression data is supporting context only.
HPA tissue expression evidence for CFI
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 |
|---|---|---|---|---|
| Testis | Reported tissue cells | High | Protein (HPA) | HPA → |
| Bronchus | Reported tissue cells | Medium | Protein (HPA) | HPA → |
| Duodenum | Reported tissue cells | Medium | Protein (HPA) | HPA → |
| Fallopian tube | Reported tissue cells | Low | Protein (HPA) | HPA → |
Section 3
Advanced CFI Western Blot Tips
Deeper troubleshooting and optimisation questions for CFI, answered from its protein features.
Which band should guide the blot?
Use 65.8 kDa, the observation attached to the authoritative PB9935 WB record.
How should calculated mass be interpreted?
Treat the UniProt calculated mass as context; it does not replace the catalog-observed 65.8 kDa expectation.
Which positive control should I start with?
Start with Testis, the lead HPA protein-expression candidate.
Which negative control is defensible?
Use Appendix 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 CFI Western blot?
Use the transfer method in the recommended protocol and verify transfer before blocking.
How should PB9935 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
CFI Western Blot Reagents
Human/Rat-reactive CFI Western blot reagents with authoritative product imagery.
Real WB data
Anti-Factor I/CFI Antibody Picoband®
Cat # PB9935
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 P05156
- Human Protein Atlas — CFI
- PB9935 product record
- PMC11781327 — CAMK2D and Complement Factor I-Involved Calcium/Calmodulin Signaling Modulates Sodium Iodate-Induced Mouse Retinal Degeneration (Investigative ophthalmology & visual science, 2025)
- PMC7889977 — A Candidate Prognostic Biomarker Complement Factor I Promotes Malignant Progression in Glioma (Frontiers in cell and developmental biology, 2020)
- PMC3458969 — Complement factor I deficiency: a not so rare immune defect: characterization of new mutations and the first large gene deletion (Orphanet journal of rare diseases, 2012)