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- Table of Contents
POLK / DNA polymerase kappa · Western blot design guide
Design a Western Blot for POLK
Real validated POLK Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-POLK 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
POLK 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 | ~98.8 kDa | |
| Gel | 8–10% (standard starting point) | |
| Negative control | Suggested KO / knockdown lysate |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | — | |
| Caveat | — | |
| Gene-set association | MSigDB C7 membership | |
| Isoform | 8 isoform(s) |
Section 1
Real Curated POLK Western Blot Protocols
The A01987-1 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | extracts of various cell lines, (catalog A01987-1) |
| Gel % | 8–10% (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 | Blocking buffer: 3% nonfat dry milk in TBST (catalog A01987-1) |
| Primary antibody | A01987-1 · 1:1000 (catalog A01987-1) |
| Primary incubation | Overnight at 4 °C (standard starting point) |
| Secondary antibody | Goat Anti-Rabbit IgG, 1:10000 (catalog A01987-1) |
| Secondary incubation | 1 h at room temperature (standard starting point) |
| Wash | 3 × 5 min in TBST (standard starting point) |
| Detection | ECL (catalog A01987-1) |
Section 2
What Is the Expected POLK Western Blot Band Size?
POLK is predicted at 98.8 kDa; eight isoforms could affect migration, but no distinct isoform bands or empirical band size are demonstrated.
| Band near 98.8 kDa | Consistent with the predicted POLK mass; confirm identity with controls |
| Single sharp band | Annotated isoforms may be absent or unresolved |
| Two bands at different positions | Could reflect expressed isoforms if both bands are confirmed as POLK |
| Several discrete bands | Could reflect multiple expressed isoforms; their migration is unverified |
💡Expected POLK appearancePOLK has a predicted mass of 98.8 kDa and eight annotated isoforms, but no empirical band size or isoform migration is supplied; confirm any candidate band with ordinary band-identity controls.
| Predicted POLK mass | Sets a 98.8 kDa reference for the supplied sequence |
| Isoforms 1, 2 and 3 | May differ in size; individual masses and migration are unknown |
| Isoforms 4, 5 and 6 | May differ in size; individual masses and migration are unknown |
| Isoforms 7 and 8 | May differ in size; individual masses and migration are unknown |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | Nuclear POLK may be difficult to detect in whole-cell lysate | Check a nuclear-enriched fraction and a positive control |
| Band higher than expected | Its identity is uncertain; no listed modification establishes an upward shift | Compare with a positive control and verify antibody specificity |
| Band lower than expected | An alternative isoform is possible, but its mass is unknown | Confirm POLK identity with a second antibody or POLK-depleted sample |
| Multiple bands | Expressed isoforms are possible, but distinct migration is unverified | Compare bands with a POLK-depleted control |
| Weak or no signal | Nuclear localization may limit signal in the tested lysate | Check a nuclear-enriched fraction and confirm antibody performance with a positive control |
Experiment evidence
Western blot images showing POLK band
A01987-1 · POLK
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for POLK Western blot
🧪For positive controls for POLK in Western blot, you can use no HPA-supported tissue or cell line from the supplied evidence.
Positive control: No high/medium HPA tissue identified
Negative control: Suggested KO / knockdown lysate
Loading controls: Run GAPDH, β-actin, and a total-protein stain alongside the samples.
⚠️Feasibility: HPA provides no tissue data, so suitable tissue controls cannot be verified.
HPA tissue expression evidence for POLK
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 |
|---|---|---|---|---|
| No high/medium HPA tissues identified in the supplied evidence. | ||||
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| No lower-expression tissue rows available in the supplied evidence. | ||||
Section 3
Advanced POLK Western Blot Tips
Deeper troubleshooting and optimisation questions for POLK, answered from its protein features.
How should POLK 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.
Which POLK isoforms could produce smaller bands?
Isoforms · Eight isoforms are listed. Relative to the 870-residue canonical sequence, isoform 3 lacks residues 312–509; isoforms 2, 4, 5, 6 and 7 lack substantial C-terminal segments. Isoforms 4, 7 and 8 also lack residues 1–90. These sequence differences could change band positions, but the features do not establish where any isoform runs.
Are annotated modifications available to explain a POLK band shift?
PTM · No modified residues or glycosylation sites are listed in the supplied features. Do not assign a shifted band to a specific modification from this record. Isoform sequence differences are documented, but they also do not establish the cause of an observed shift.
Does UV irradiation induce POLK protein abundance?
Induction · The supplied location feature says POLK is recruited to DNA damage sites after ultraviolet irradiation. It does not say total POLK abundance increases. Compare matched samples if testing abundance, and distinguish a change in localization from a change in total signal.
How should transfer be checked for POLK?
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 A01987-1 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 POLK Western blot signal be quantified after DNA damage?
Quantitation · POLK is detected throughout the nucleus and at replication foci, and is recruited to DNA damage sites after ultraviolet irradiation. Quantify comparable sample fractions and loading across conditions. A change in signal from a selected fraction may reflect redistribution; these features alone do not establish a change in total protein abundance.
Should POLK run at its predicted 98.8 kDa?
Interpretation · 98.8 kDa is the predicted mass for canonical POLK. No observed band position is supplied, so an apparent mass difference cannot be assessed from these features alone. Use a molecular weight marker and consider which isoform the antibody detects.
Check the epitope against the UniProt coordinates. An epitope in residues 1–90 is absent from isoforms 4, 7 and 8. An epitope in residues 490–870 is absent from isoforms 2, 4, 5, 6 and 7; isoform 3 lacks residues 312–509. This helps identify which isoforms the antibody could detect.
First compare each band's position with the 98.8 kDa canonical prediction and the listed alternative sequences. Several isoforms delete large regions, while isoforms 2, 4, 5, 6 and 7 also replace sequence near residues 453–472. Check whether the antibody epitope is retained. With no observed band or modification site supplied, these features cannot identify an unexpected band by themselves.
Check the epitope against the UniProt coordinates. An epitope in residues 1–90 is absent from isoforms 4, 7 and 8. An epitope in residues 490–870 is absent from isoforms 2, 4, 5, 6 and 7; isoform 3 lacks residues 312–509. This helps identify which isoforms the antibody could detect.
First compare each band's position with the 98.8 kDa canonical prediction and the listed alternative sequences. Several isoforms delete large regions, while isoforms 2, 4, 5, 6 and 7 also replace sequence near residues 453–472. Check whether the antibody epitope is retained. With no observed band or modification site supplied, these features cannot identify an unexpected band by themselves.
Boster reagents
POLK 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-DNA polymerase kappa POLK Antibody
Cat # A01987-1
The catalog reports an anti-POLK antibody for Western blotting with reported human, mouse, and rat reactivity. Its WB image uses cell-line extracts at a 1:1000 primary dilution and 25 µg protein per lane; the caption does not identify the cell lines.
Which to pick: A01987-1 is the only listed option and has a WB image. Check its reported reactivity against your sample species, then use the caption’s 1:1000 primary dilution as a starting point.
Source: BosterBio POLK gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry Q9UBT6.
- Human Protein Atlas. POLK tissue expression.
- PMC5450631 — target-verified WB comparison
- PMC13345371 — target-verified WB comparison