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- Table of Contents
MAFB / Transcription factor MafB · Western blot design guide
Design a Western Blot for MAFB
Real validated MAFB Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-MAFB WB antibodies. Everything you need to plan the experiment before you commit precious samples.
Evidence assembled September 2026 · For research use; verify linked source records and product datasheet before use
MAFB Western Blot Experimental Design Guide
Expected bands, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before running
| Expected band | ~35.8 kDa | |
| Gel | 12–15% (standard starting point) | |
| Positive control | Parathyroid gland (IHC candidate; verify WB) +4 more | |
| Negative control | Adipose tissue (IHC candidate; verify WB) |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Ubl conjugation | |
| Caveat | Modification-state controls | |
| Gene-set association | MSigDB Hallmark membership | |
| Isoform | 1 isoform(s) |
Section 1
Real Curated MAFB Western Blot Protocols
The A02446 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | extracts of various cells, (catalog A02446) |
| Gel % | 12–15% (standard starting point) |
| Load | 20–30 µg total protein per lane; optimize for abundance (standard starting point) |
| Transfer | Standard semi-dry transfer; verify efficiency (standard starting point) |
| Membrane | 0.45 µm PVDF (standard starting point) |
| Blocking | 5% milk or 5% BSA in TBST (standard starting point) |
| Primary antibody | A02446; use the WB datasheet starting dilution (standard starting point) |
| Primary incubation | Overnight at 4 °C (standard starting point) |
| Secondary antibody | Species-matched HRP conjugate at validated dilution (standard starting point) |
| Secondary incubation | 1 h at room temperature (standard starting point) |
| Wash | 3 × 5 min in TBST (standard starting point) |
| Detection | ECL; bracket exposures to avoid saturation (standard starting point) |
Section 2
What Is the Expected MAFB Western Blot Band Size?
MafB has a predicted monomer size of 35.8 kDa; homodimer formation could affect migration if complexes persist, but no empirical band demonstrates that effect.
| Band near 35.8 kDa | Consistent with predicted MafB monomer; confirm identity with controls |
| Band near 72 kDa | Could reflect retained MafB homodimer if the complex survives sample preparation |
| Stronger band in nuclear than cytosolic extract | Consistent with MafB nuclear localization |
| Little or no band in cytosolic extract | MafB may be concentrated in the nuclear fraction |
💡Expected MAFB appearanceUniProt predicts a 35.8 kDa MafB monomer, but no empirical band size is supplied; confirm any candidate band with nuclear enrichment and an antibody specificity control.
| Predicted MafB monomer mass | Provides a 35.8 kDa reference, not a measured migration |
| MafB homodimer formation | Could produce a band near twice the monomer size if the complex survives preparation |
| MafB heterodimer with FOS | Does not establish a distinct band size under denaturing conditions |
| MafB heterodimer with FOSB or FOSL2 | Does not establish a distinct band size under denaturing conditions |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | Nuclear MafB may be poorly represented in the sample | Check nuclear extraction and a positive control |
| Band higher than expected | A retained MafB complex or an unrelated antibody target is possible | Check denaturation and confirm identity by MafB depletion |
| Band lower than expected | Proteolysis or an unrelated antibody target is possible | Use protease inhibitors and confirm identity by MafB depletion |
| Multiple bands | Band identities are unresolved; MafB forms protein complexes | Compare fully denatured samples and use MafB depletion |
| Weak or no signal | The sample may contain little nuclear MafB | Enrich the nuclear fraction and include a positive control |
| Fragments below expected size | MafB may have degraded during preparation | Prepare fresh samples with protease inhibitors |
Experiment evidence
Western blot images showing MAFB band
A02446 · MAFB
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for MAFB Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for MAFB in Western blot, you can use parathyroid gland tissue, which shows high expression in HPA.
Positive control: Parathyroid gland (IHC candidate; verify WB)
Negative control: Adipose tissue (IHC candidate; verify WB)
Loading controls: Run GAPDH, β-actin, and a total-protein stain such as Ponceau alongside the samples.
⚠️Feasibility: A nuclear-enriched lysate may improve detection of nuclear MAFB.
HPA tissue expression evidence for MAFB
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.
Higher expression tissues · candidate positive controls from IHC
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Parathyroid gland | glandular cells | High | Protein (IHC) | HPA → |
| Testis | pachytene spermatocytes | High | Protein (IHC) | HPA → |
| Bone marrow | hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Cerebellum | cells in granular layer | Medium | Protein (IHC) | HPA → |
| Cerebral cortex | endothelial cells | Medium | Protein (IHC) | HPA → |
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | adipocytes | Not detected | Protein (IHC) | HPA → |
| Gallbladder | glandular cells | Not detected | Protein (IHC) | HPA → |
| Heart muscle | cardiomyocytes | Not detected | Protein (IHC) | HPA → |
| Liver | cholangiocytes | Not detected | Protein (IHC) | HPA → |
| Ovary | follicle cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced MAFB Western Blot Tips
Deeper troubleshooting and optimisation questions for MAFB, answered from its protein features.
Where should the main MAFB band appear?
Band shift · MAFB has a predicted mass of 35.8 kDa. Use that as a starting point for identifying a band; no observed band position is supplied, and the listed features do not establish an apparent mass.
Do the supplied features support multiple MAFB isoform bands?
Isoforms · Only one isoform is listed, with a 323-residue canonical sequence and no alternative sequence. The supplied features therefore do not identify another isoform to explain a second band.
Could ubiquitin-like modification affect MAFB bands?
PTM · Ubl conjugation and isopeptide bond are listed as keywords, but no modified residue or coordinate is supplied. These annotations alone do not establish a visible shift or explain a band above 35.8 kDa.
Does this guide establish induction of MAFB?
Induction · No general induction response is established by this guide. A pathway or gene-set association is not evidence of induction in a particular specimen. Verify the relevant treatment and control in a target-specific experiment.
How should transfer be checked for MAFB?
Transfer · Standard workflow guidance: verify transfer efficiency for the intended target size before interpreting a weak signal. Use total-protein assessment and optimize transfer for the membrane, gel and apparatus; the labelled catalog values take precedence.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the A02446 datasheet where specified. Otherwise compare 5% milk or 5% BSA in TBST; for a phospho-specific assay start with BSA. Optimize background and specific signal with matched controls.
How should MAFB be quantified?
Quantitation · Standard workflow guidance: quantify only a validated target band within the linear exposure range. Use consistent sample preparation and loading, retain biological replicates, and avoid interpreting saturation or loading differences as regulation.
Which sample fraction is relevant for detecting MAFB?
Interpretation · MAFB is annotated as nuclear. Include the nuclear fraction when preparing samples, and compare equivalent fractions across conditions so differences in recovery are less likely to affect interpretation.
MAFB is annotated to form homodimers and heterodimers, including with FOS, FOSB and FOSL2. A higher band is not proof of a dimer: the supplied features do not show whether these complexes persist during Western blot sample preparation.
Compare bands from consistently prepared samples and account for differences in nuclear recovery. The nuclear annotation makes fraction choice relevant; the supplied features provide no observed band position to validate band identity by mass alone.
Check each band's position against the predicted 35.8 kDa mass and assess band identity independently. One isoform is listed, while the Ubl conjugation keywords provide no site or demonstrated shift. Dimerization is annotated, but does not establish that an extra band represents a complex.
MAFB is annotated to form homodimers and heterodimers, including with FOS, FOSB and FOSL2. A higher band is not proof of a dimer: the supplied features do not show whether these complexes persist during Western blot sample preparation.
Compare bands from consistently prepared samples and account for differences in nuclear recovery. The nuclear annotation makes fraction choice relevant; the supplied features provide no observed band position to validate band identity by mass alone.
Check each band's position against the predicted 35.8 kDa mass and assess band identity independently. One isoform is listed, while the Ubl conjugation keywords provide no site or demonstrated shift. Dimerization is annotated, but does not establish that an extra band represents a complex.
Boster reagents
MAFB Western Blot Antibodies
Catalog antibodies with Western blot application and product-specific WB images. Evaluate suitability with the reported sample, controls and experimental conditions.
Real WB data
Anti-Transcription factor MafB MAFB Antibody
Cat # A02446
The catalog reports A02446 as an anti-MAFB antibody with reported Human, Mouse, and Rat reactivity. A Western blot image is available, described as analysis of extracts from various cells; the supplied caption does not identify the cells or conditions.
Which to pick: A02446 is the only listed MAFB antibody and has a Western blot image. Match its reported reactivity to your sample, and check the image and full product details for suitability.
Source: BosterBio MAFB gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry Q9Y5Q3.
- Human Protein Atlas. MAFB tissue expression.
- PMC8101704 — target-verified WB comparison
- PMC6692491 — target-verified WB comparison
- PMC13398965 — target-verified WB comparison