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- Table of Contents
MAP4 / Microtubule-associated protein 4 · Western blot design guide
Design a Western Blot for MAP4
Real validated MAP4 Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-MAP4 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
MAP4 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 | ~121 kDa | |
| Observed band | ~210 kDa | |
| Gel | 8% (catalog A00948-2) | |
| Positive control | Caudate (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 | Phosphorylated + Acetylated | |
| Caveat | Observed mass discrepancy | |
| Gene-set association | MSigDB C7 membership | |
| Isoform | 7 isoform(s) |
Section 1
Real Curated MAP4 Western Blot Protocols
The A00948-2 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | human Hela, human 293T, human HepG2 (catalog A00948-2) |
| Gel % | 8% (catalog A00948-2) |
| Load | 30 ug; reducing conditions (catalog A00948-2) |
| Transfer | a nitrocellulose membrane at 150 mA for 50-90 minutes (catalog A00948-2) |
| Membrane | nitrocellulose membrane (catalog A00948-2) |
| Blocking | 5% non-fat milk/TBS for 1.5 hour at RT (catalog A00948-2) |
| Primary antibody | A00948-2 · 1:1000 (catalog A00948-2) |
| Primary incubation | overnight at 4°C (catalog A00948-2) |
| Secondary antibody | goat anti-rabbit IgG-HRP, 1:5000 (catalog A00948-2) |
| Secondary incubation | 1.5 hour at RT (catalog A00948-2) |
| Wash | TBS-0.1%Tween 3 times with 5 minutes each (catalog A00948-2) |
| Detection | ECL (catalog A00948-2) |
Section 2
What Is the Expected MAP4 Western Blot Band Size?
MAP4 is predicted at 121 kDa but observed near 210 kDa in reducing blots; the cause of the difference is not established.
| Band near 210 kDa | Empirical MAP4 band in reducing whole-cell lysates; the cause of migration above the predicted mass is unestablished |
| Band near 121 kDa | Matches the sequence-predicted MAP4 mass; identity requires confirmation |
| Several discrete bands | Could reflect MAP4 isoforms 1–7, though distinct migration has not been demonstrated |
| Closely spaced bands | Could reflect different phosphorylation states; a visible shift has not been established |
| Weak or absent lysate band | Cytoskeletal MAP4 may be poorly recovered during extraction |
💡Expected MAP4 appearanceMAP4 has a predicted mass of 121 kDa, while antibody QC detects a band near 210 kDa in reducing whole-cell lysates; its migration difference remains unexplained, so confirm band identity with appropriate controls.
| UniProt predicted mass | 121 kDa from sequence; the observed band is near 210 kDa for an unestablished reason |
| Splice isoform 1 | Its individual apparent mass is not supplied |
| Splice isoforms 2 and 3 | Sequence differences may affect size, but their apparent masses are not supplied |
| Splice isoforms 4, 5, 6 and 7 | Sequence differences may affect size, but their apparent masses are not supplied |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | Cytoskeletal MAP4 may be poorly extracted | Check extraction of the cytoskeletal fraction and sample loading |
| Band higher than expected | The observed 210 kDa band exceeds the 121 kDa prediction; the cause is unestablished | Compare with the QC lysates and confirm identity by MAP4 depletion |
| Band lower than expected | An isoform or nonspecific antibody binding is possible; isoform masses are unknown | Confirm identity by MAP4 depletion and compare antibodies |
| Broad smear instead of sharp band | Different modification states are possible, but their effect on migration is unproven | Check sample preparation and compare treated and untreated lysates |
| Multiple bands | Seven splice isoforms and documented phosphorylation offer possible explanations | Use MAP4 depletion to identify specific bands; compare phosphatase-treated lysate if needed |
| Weak or no signal | Cytoskeletal MAP4 may be underrepresented in the soluble sample | Assess the cytoskeletal fraction and verify transfer and loading |
Experiment evidence
Western blot images showing MAP4 band
A00948-2 · MAP4
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for MAP4 Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for MAP4 in Western blot, you can use caudate tissue, which HPA scores High.
Positive control: Caudate (IHC candidate; verify WB)
Negative control: Adipose tissue (IHC candidate; verify WB)
Loading controls: Run GAPDH, β-actin, and a total-protein stain alongside the samples.
⚠️Feasibility: HPA reports High expression in caudate and no detection in adipose tissue, making tissue controls feasible.
HPA tissue expression evidence for MAP4
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 |
|---|---|---|---|---|
| Caudate | glial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Bergmann glia - cytoplasm/membrane | High | Protein (IHC) | HPA → |
| Cerebral cortex | endothelial cells | High | Protein (IHC) | HPA → |
| Cervix | squamous epithelial cells | High | Protein (IHC) | HPA → |
| Colon | endothelial cells | High | 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 → |
| Adrenal gland | glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Nasopharynx | respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
| Parathyroid gland | glandular cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced MAP4 Western Blot Tips
Deeper troubleshooting and optimisation questions for MAP4, answered from its protein features.
How should MAP4 band migration be interpreted?
Band shift · Use the separately labelled calculated mass and catalog-observed evidence above. A sequence annotation does not establish an observed migration shift. Verify target identity with orthogonal controls.
Could MAP4 isoforms produce different bands?
Isoforms · Yes. Seven isoforms are listed, with substantial sequence differences. Isoform 2 lacks residues 558–730, isoform 3 lacks residues 717–1152, and isoform 7 lacks residues 100–1152. Compare band patterns with the isoforms expressed in your sample; do not identify an isoform from band position alone.
Check the antibody epitope against the isoform sequences. For example, an epitope within canonical residues 558–730 is absent from isoform 2, while one within residues 717–1152 is absent from isoform 3. UniProt coordinates here refer to the supplied canonical sequence; antibody or paper numbering may differ.
Check the antibody epitope against the isoform sequences. For example, an epitope within canonical residues 558–730 is absent from isoform 2, while one within residues 717–1152 is absent from isoform 3. UniProt coordinates here refer to the supplied canonical sequence; antibody or paper numbering may differ.
Which MAP4 modifications matter when interpreting band patterns?
PTM · The supplied features list many phosphoserine and phosphothreonine sites, including Ser941 and Thr942, plus N-acetylalanine at position 2. These sites make modification-dependent patterns worth investigating, but their presence does not establish a visible shift. Use the supplied canonical UniProt coordinates when comparing site-specific reagents.
Does this guide establish induction of MAP4?
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.
What transfer method to use for MAP4 Western blot?
Transfer · The observed MAP4 band is near 210 kDa, so assess transfer of proteins around that apparent size. Check whether the band leaves the gel and reaches the membrane before interpreting a weak signal. The supplied features do not specify a particular transfer method.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the A00948-2 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.
What should be considered when quantifying MAP4 bands?
Quantitation · Define whether the measurement represents the approximately 210 kDa band or all confirmed MAP4 bands. The seven isoforms can differ in sequence and antibody epitope retention, so one band may not represent total MAP4. Apply the same band definition across samples and report it explicitly.
Why might MAP4 appear near 210 kDa instead of its predicted 121 kDa?
Interpretation · The supplied blots show an apparent band near 210 kDa, while the predicted mass is 121 kDa. MAP4 has multiple isoforms and modification sites, but those features alone do not explain the difference. Confirm the band’s identity before assigning a cause.
First compare them with the approximately 210 kDa observed band and the seven listed isoforms. Sequence changes are extensive in several isoforms, and MAP4 has many modification sites. Neither feature proves the identity of another band; verify it with an antibody to a different retained region or another independent identification method.
First compare them with the approximately 210 kDa observed band and the seven listed isoforms. Sequence changes are extensive in several isoforms, and MAP4 has many modification sites. Neither feature proves the identity of another band; verify it with an antibody to a different retained region or another independent identification method.
Boster reagents
MAP4 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-MAP4 Antibody Picoband®
Cat # A00948-2
A00948-2 is a rabbit polyclonal anti-MAP4 antibody with a Western blot image from four human cell lysates. The reported band is approximately 210 kDa, versus an expected 121 kDa; the supplied evidence does not resolve this discrepancy.
Which to pick: A00948-2 is the only listed option. Its stated reactivity is human, mouse, and rat, but the supplied Western blot image uses human HeLa, 293T, HepG2, and U251 lysates only. Consider the reported band-size discrepancy when interpreting results.
Source: BosterBio MAP4 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry P27816.
- Human Protein Atlas. MAP4 tissue expression.
- PMC9959477 — target-verified WB comparison
- PMC10054043 — target-verified WB comparison
- PMC3229508 — target-verified WB comparison