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- Table of Contents
KRT4 / Keratin, type II cytoskeletal 4 · Western blot design guide
Design a Western Blot for KRT4
Source-linked KRT4 Western blot protocol options, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-KRT4 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
KRT4 Western Blot Experimental Design Guide
Expected bands, source-linked protocol options, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before running
| Expected band | ~56.1 kDa | |
| Observed band | ~56 kDa | |
| Gel | 5–20% (catalog A07410-3) | |
| Positive control | Cervix (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 | Methylated | |
| Caveat | Modification-state controls | |
| Gene-set association | MSigDB Hallmark membership | |
| Isoform | 1 isoform(s) |
Section 1
Source-Linked KRT4 Western Blot Protocol Options
The A07410-3 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | human Hacat (catalog A07410-3) |
| Gel % | 5–20% (catalog A07410-3) |
| Load | 30 ug; reducing conditions (catalog A07410-3) |
| Transfer | a nitrocellulose membrane at 150 mA for 50-90 minutes (catalog A07410-3) |
| Membrane | nitrocellulose membrane (catalog A07410-3) |
| Blocking | 5% non-fat milk/TBS for 1.5 hour at RT (catalog A07410-3) |
| Primary antibody | A07410-3 · 0.5 μg/mL (catalog A07410-3) |
| Primary incubation | overnight at 4°C (catalog A07410-3) |
| Secondary antibody | goat anti-rabbit IgG-HRP, 1:5000 (catalog A07410-3) |
| Secondary incubation | 1.5 hour at RT (catalog A07410-3) |
| Wash | TBS-0.1%Tween 3 times with 5 minutes each (catalog A07410-3) |
| Detection | ECL (catalog A07410-3) |
Section 2
What Is the Expected KRT4 Western Blot Band Size?
KRT4 is predicted at 56.1 kDa and observed at ~56 kDa; the supplied evidence does not establish a cause for the small difference.
| Band at ~56 kDa | Matches the observed KRT4 band and its predicted monomer size |
| Single sharp band near 56 kDa | Consistent with KRT4; Arg13 methylation does not establish a visible shift |
| Weak or absent band in a soluble lysate fraction | Filament-associated KRT4 may require more complete extraction |
| Additional bands beside ~56 kDa | Their identity is unestablished; verify the ~56 kDa band with specificity controls |
💡Expected KRT4 appearanceKRT4 has a predicted mass of 56.1 kDa and an observed band at ~56 kDa; confirm band identity with appropriate antibody specificity controls.
| Predicted KRT4 mass | Places the monomer near 56.1 kDa |
| Omega-N-methylarginine at Arg13 | Does not establish a resolvable mobility shift |
| KRT4 and KRT13 heterotetramer | Assembly does not establish a larger band under the supplied reducing blot conditions |
| Single listed isoform | Provides no evidence for distinct isoform band sizes |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | Filament-associated KRT4 may be incompletely extracted | Check the insoluble fraction and extraction conditions |
| Band higher than expected | The band identity or migration is uncertain | Compare with the ~56 kDa band and use an independent antibody or KRT4 depletion control |
| Band lower than expected | Possible degradation or an unrelated antibody target | Use fresh protected lysate and verify identity with KRT4 depletion |
| Multiple bands | Additional bands are not explained by a supplied isoform or glycosylation feature | Check specificity with KRT4 depletion and an independent antibody |
| Weak or no signal | Low KRT4 recovery from filament-containing material | Check extraction and include a KRT4-positive sample |
| Fragments below expected size | Possible proteolysis during sample preparation | Prepare fresh lysate with protease inhibitors and verify KRT4 identity |
Experiment evidence
Western blot images showing KRT4 band
A07410-3 · KRT4
M07410 · KRT4
M07410-1 · KRT4
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for KRT4 Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for KRT4 in Western blot, you can use cervix tissue.
Positive control: Cervix (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 rates the positive tissues Medium, so obtaining a strong positive signal may require optimization.
HPA tissue expression evidence for KRT4
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 |
|---|---|---|---|---|
| Cervix | glandular cells | Medium | Protein (IHC) | HPA → |
| Esophagus | squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Oral mucosa | squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Tonsil | squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Vagina | squamous epithelial 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 → |
| Adrenal gland | glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced KRT4 Western Blot Tips
Deeper troubleshooting and optimisation questions for KRT4, answered from its protein features.
How should KRT4 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 KRT4 isoforms explain multiple bands?
Isoforms · This entry lists one isoform and no alternative sequence. It provides no isoform-based explanation for multiple bands; assess additional bands separately before assigning them to KRT4.
Which KRT4 modification should be considered when interpreting a band?
PTM · UniProt lists omega-N-methylarginine at residue 13, using UniProt sequence numbering. Other numbering conventions may differ. The listed modification alone does not establish a visible band shift.
Does this guide establish induction of KRT4?
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 KRT4 Western blot?
Transfer · KRT4 is a 520-residue intermediate-filament protein with a predicted mass of 56.1 kDa. Check that your transfer captures proteins near 56 kDa. These features do not specify a particular transfer method.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the A07410-3 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 KRT4 quantitation focus on?
Quantitation · Quantify a consistently defined band near the observed 56 kDa position across samples. The supplied features identify one isoform, so they do not provide separate isoform targets for quantitation.
How does the observed KRT4 band compare with its predicted mass?
Interpretation · The observed band is about 56 kDa, close to KRT4’s predicted 56.1 kDa. The supplied features do not establish a meaningful mass difference or a visible modification-dependent shift.
Use the expected approximately 56 kDa band as a reference. The entry lists one isoform and one modified residue, but neither feature establishes the identity of an additional band. Do not assign extra bands to isoforms or methylation from position alone.
KRT4 is generally associated with KRT13 in a heterotetramer containing two type I and two type II keratins. A KRT4 band indicates KRT4 detection; it does not by itself measure KRT13 or establish that the tetramer remains intact.
Use the expected approximately 56 kDa band as a reference. The entry lists one isoform and one modified residue, but neither feature establishes the identity of an additional band. Do not assign extra bands to isoforms or methylation from position alone.
KRT4 is generally associated with KRT13 in a heterotetramer containing two type I and two type II keratins. A KRT4 band indicates KRT4 detection; it does not by itself measure KRT13 or establish that the tetramer remains intact.
Boster reagents
KRT4 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-Cytokeratin 4/KRT4 Antibody Picoband®
Cat # A07410-3
Real WB data
Anti-Cytokeratin 4 KRT4 Rabbit Monoclonal Antibody
Cat # M07410
Real WB data
Anti-Cytokeratin 4 KRT4 Rabbit Monoclonal Antibody
Cat # M07410-1
Three the supplier anti-KRT4 antibodies have WB images: A07410-3 shows an approximately 56 kDa band in human HaCaT lysate, while M07410 and M07410-1 show A431 lysate blots. No publication or independent validation evidence is supplied.
Which to pick: Choose A07410-3 for its documented HaCaT WB conditions. M07410 and M07410-1 show A431 WB images; M07410 also lists rat reactivity, but the supplied WB evidence does not demonstrate rat testing.
Source: BosterBio KRT4 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry P19013.
- Human Protein Atlas. KRT4 tissue expression.
- PMC10835169 — target-verified WB comparison
- PMC11096375 — target-verified WB comparison