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- Table of Contents
QKI / KH domain-containing RNA-binding protein QKI · Western blot design guide
Design a Western Blot for QKI
Real validated QKI Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-QKI 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
QKI 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 | ~37.7 kDa | |
| Observed band | ~38 kDa | |
| Gel | 5–20% (catalog M01874) | |
| Positive control | Caudate (IHC candidate; verify WB) +4 more | |
| Negative control | Breast (IHC candidate; verify WB) |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Phosphorylated + Methylated | |
| Caveat | Modification-state controls | |
| Gene-set association | MSigDB C7 membership | |
| Isoform | 6 isoform(s) |
Section 1
Real Curated QKI Western Blot Protocols
The M01874 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | human K562, human U251, human HEL (catalog M01874) |
| Gel % | 5–20% (catalog M01874) |
| Load | 30 ug; reducing conditions (catalog M01874) |
| Transfer | a nitrocellulose membrane at 150 mA for 50-90 minutes (catalog M01874) |
| Membrane | nitrocellulose membrane (catalog M01874) |
| Blocking | 5% non-fat milk/TBS for 1.5 hour at RT (catalog M01874) |
| Primary antibody | M01874 · 1:500 (catalog M01874) |
| Primary incubation | overnight at 4°C (catalog M01874) |
| Secondary antibody | goat anti-rabbit IgG-HRP, 1:5000 (catalog M01874) |
| Secondary incubation | 1.5 hour at RT (catalog M01874) |
| Wash | TBS-0.1%Tween 3 times with 5 minutes each (catalog M01874) |
| Detection | ECL (catalog M01874) |
Section 2
What Is the Expected QKI Western Blot Band Size?
QKI is predicted at 37.7 kDa and observed at ~38 kDa; the small difference has no established cause in the supplied evidence.
| Band at ~38 kDa | QKI-sized band matching the empirical whole-cell lysate result; confirm identity with an antibody control |
| Several bands at different positions | QKI splice isoforms could contribute, but distinct migration has not been established |
| Higher band near twice the monomer size | Could reflect a QKI homodimer that persists during sample preparation |
| Single ~38 kDa band without a higher band | Consistent with detection of denatured QKI monomer |
💡Expected QKI appearanceUniProt predicts a 37.7 kDa QKI monomer, and antibody QC detects a band at ~38 kDa in whole-cell lysates; confirm band identity with standard controls.
| UniProt predicted monomer mass | Predicts 37.7 kDa; the empirical band is ~38 kDa |
| QKI homodimer formation | May produce a higher band if the dimer survives sample preparation |
| QKI5, QKI6, QKI7 and QKI7B splice isoforms | May differ in apparent size; their individual masses and migration are not supplied |
| Splice isoforms 2 and 3 | May differ in apparent size; their individual masses and migration are not supplied |
| Situation | Likely cause | Next action |
|---|---|---|
| Band higher than expected | QKI homodimer may persist during sample preparation | Check denaturation conditions and compare with a QKI knockdown control |
| Band lower than expected | A splice isoform or protein breakdown is possible | Compare with a QKI knockdown and use an antibody to another epitope |
| Multiple bands | Six QKI splice isoforms are annotated, though distinct migration is unproven | Check which bands decrease after QKI knockdown |
| Weak or no signal | QKI recovery from nuclear and cytoplasmic fractions may vary | Check loading and antibody performance with a positive lysate, then examine both fractions |
| Fragments below expected size | Protein degradation during sample handling is possible | Process samples promptly with protease inhibitors and verify bands using QKI knockdown |
Experiment evidence
Western blot images showing QKI band
M01874 · QKI
A01874-3 · QKI
A01874-3 · QKI
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for QKI Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for QKI in Western blot, you can use caudate tissue, which has high HPA expression.
Positive control: Caudate (IHC candidate; verify WB)
Negative control: Breast (IHC candidate; verify WB)
Loading controls: Run GAPDH, β-actin, and a total-protein stain alongside.
⚠️Feasibility: QKI is intracellular, and HPA identifies a not-detected tissue for a negative control.
HPA tissue expression evidence for QKI
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 | glial cells | High | Protein (IHC) | HPA → |
| Placenta | trophoblastic cells | High | Protein (IHC) | HPA → |
| Soft tissue | fibroblasts | High | Protein (IHC) | HPA → |
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Breast | adipocytes | Not detected | Protein (IHC) | HPA → |
| Bronchus | respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
| Cervix | glandular cells | Not detected | Protein (IHC) | HPA → |
| Duodenum | glandular cells | Not detected | Protein (IHC) | HPA → |
| Fallopian tube | glandular cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced QKI Western Blot Tips
Deeper troubleshooting and optimisation questions for QKI, answered from its protein features.
How should QKI 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 QKI isoforms produce different bands?
Isoforms · Yes. UniProt lists six isoforms. Isoforms 2 and 3 lack residues 213–220; isoforms 3, QKI7, QKI6 and QKI7B have different sequences replacing residues 312–341. Consider which isoforms the antibody can recognize when interpreting multiple bands.
Specify whether the measurement is intended to represent one isoform or all recognized QKI isoforms. UniProt lists six isoforms with sequence differences, so a single band's intensity may not represent total QKI. Compare the same defined band or set of bands across samples.
Specify whether the measurement is intended to represent one isoform or all recognized QKI isoforms. UniProt lists six isoforms with sequence differences, so a single band's intensity may not represent total QKI. Compare the same defined band or set of bands across samples.
Which QKI modification sites matter when interpreting bands?
PTM · In UniProt coordinates, QKI has phosphoserine at 188 and methylarginine at 227, 242 and 256. At 242, asymmetric dimethylarginine by CARM1 and omega-N-methylarginine are listed as alternate modifications. These features alone do not establish a visible band shift.
UniProt lists phosphoserine at position 188, using its own sequence numbering. This identifies a modification to consider, but does not show that phosphorylation causes any observed shift or account for a difference between apparent and predicted mass.
UniProt lists phosphoserine at position 188, using its own sequence numbering. This identifies a modification to consider, but does not show that phosphorylation causes any observed shift or account for a difference between apparent and predicted mass.
Does this guide establish induction of QKI?
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 QKI?
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 M01874 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 QKI 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.
Does the ~38 kDa band match QKI's predicted mass?
Interpretation · Yes. The observed ~38 kDa band is close to QKI's predicted 37.7 kDa mass. That agreement supports the assignment, but band position alone does not establish identity.
UniProt places QKI in both the nucleus and cytoplasm. When comparing fractions, identify the fraction and quantify corresponding bands consistently; a change in one fraction need not describe QKI across both locations.
UniProt reports that QKI can homodimerize without RNA. A higher band alone does not establish that it is a QKI dimer; the supplied features do not show whether dimers persist under the blot conditions.
UniProt places QKI in both the nucleus and cytoplasm. When comparing fractions, identify the fraction and quantify corresponding bands consistently; a change in one fraction need not describe QKI across both locations.
UniProt reports that QKI can homodimerize without RNA. A higher band alone does not establish that it is a QKI dimer; the supplied features do not show whether dimers persist under the blot conditions.
Boster reagents
QKI 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-QK1 Rabbit Monoclonal Antibody
Cat # M01874
Real WB data
Anti-QKI Antibody Picoband®
Cat # A01874-3
The catalog reports two anti-QKI antibodies with Western blot images: monoclonal M01874 and polyclonal A01874-3. Both captions report a band at approximately 38 kDa using 30 μg of sample under reducing conditions. The supplied evidence covers the pictured samples only; no independent validation is provided.
Which to pick: For human cell lysates, both have WB images. A01874-3 also shows monkey Cos-7, rat brain and C6, and mouse brain and Neuro-2a samples. M01874’s image shows human cell lysates, although its listed reactivity includes mouse and rat.
Source: BosterBio QKI gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry Q96PU8.
- Human Protein Atlas. QKI tissue expression.
- PMC4764852 — target-verified WB comparison
- PMC6525929 — target-verified WB comparison
- PMC9464412 — target-verified WB comparison