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SKP1 / S-phase kinase-associated protein 1 · IHC design guide
Design Immunohistochemistry for SKP1
Plan chromogenic SKP1 IHC on paraffin sections using breast glandular cells as a high-staining reference (HPA tissue IHC). Assess cytoplasmic and nuclear staining, and compare it with cell populations reported as low or undetected (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SKP1 Immunohistochemistry Experimental Design Guide
Expected localisation, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before staining
| Expected localisation | Cytoplasmic and nuclear staining in most tissues (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic and nuclear signal across most tissues (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A00476-2) | |
| Positive control | Breast+4 more · see all | |
| Negative control | Appendix+3 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific) | |
| Caveat | Cell-type intensity varies across tissues (HPA tissue IHC) | |
| Regulation | No expression regulator specified (UniProt) | |
| Isoform / epitope | 2 isoforms; epitope coverage is unspecified (UniProt) |
Section 1
Recommended SKP1 IHC & IF Protocols
The catalog antibody has an IHC-P protocol (datasheet A00476-2); the published SKP1 IHC procedures below cover lung cancer, pancreatic neuroendocrine neoplasms, mouse brain and rat brain (PMC4741501; PMC7728999; PMC3542602; PMC11814243).
| Sample | Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet A00476-2) |
| Fixation | Image fixative and duration unreported (datasheet A00476-2); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A00476-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A00476-2) |
| Primary antibody | Rabbit anti-SKP1, 2-5μg/ml (datasheet A00476-2) |
| Primary incubation | Overnight at 4 °C (datasheet A00476-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A00476-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SKP1-positive staining in glandular cells of breast (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic and nuclear expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval for the catalog antibody (datasheet A00476-2). Published retrieval conditions differ; optimize for the tissue and antibody used (PMC4741501; PMC7728999; PMC3542602).
Section 2
What Is the Expected SKP1 Staining Pattern?
SKP1 staining is expected in the cytoplasm and nuclei of cells in most tissues (HPA tissue IHC: Approved; medium consistency with RNA, pending external verification). High staining is reported in breast glandular cells, bronchial respiratory epithelial cells and placental trophoblastic cells (HPA tissue IHC: High). SKP1 has no transmembrane segment, and UniProt does not annotate its subcellular location (UniProt P63208 topology and subcellular record).
| Clear cytoplasmic and nuclear staining in breast glandular cells or bronchial respiratory epithelial cells (HPA tissue IHC: High). | This matches the reported tissue pattern and provides a useful positive reference (HPA tissue IHC: cytoplasmic and nuclear expression in most tissues; High in these cells). Compare cells within the same section; a positive reference supports detection but does not establish antibody specificity on its own (general IHC practice). |
| Staining is confined to a membrane rim or extracellular deposit, without a cytoplasmic or nuclear pattern (HPA tissue IHC: expected pattern). | That distribution conflicts with the reported IHC pattern and SKP1's lack of a transmembrane segment (HPA tissue IHC; UniProt P63208 topology). Review morphology and controls for artefact before scoring it as SKP1 (general IHC practice). |
| Strong signal appears in cardiomyocytes or skeletal myocytes while the expected positive cells stain weakly (HPA tissue IHC: Not detected in those myocytes). | Treat the unexpected signal as suspect; cross-reactivity or endogenous detection activity are possibilities, not established causes (general IHC practice). Compare a reagent control and an HPA High reference before assigning cell-specific positivity (HPA tissue IHC: High in breast glandular cells). |
| Brown colour covers stroma, empty spaces and many unrelated cell types, obscuring cellular boundaries (general IHC practice). | A diffuse pattern cannot reliably establish cytoplasmic or nuclear SKP1 localisation (HPA tissue IHC: expected pattern; general IHC practice). Background from detection reagents or insufficient blocking is possible; assess controls and morphology before scoring (general IHC practice). |
| No staining appears in breast glandular cells or placental trophoblastic cells (HPA tissue IHC: High in both). | This weakens confidence in a negative call for the run (general IHC practice). Check tissue preservation and detection controls, then review the catalog antibody's IHC-P conditions; HPA staining levels do not identify a fixation effect (HPA tissue IHC; general IHC practice). |
💡Expected SKP1 appearanceCall SKP1 positive when recognisable cells show cytoplasmic and nuclear staining, especially strong staining in HPA High cell types; isolated membrane rims or diffuse tissue-wide colour are suspect (HPA tissue IHC: pattern and levels; UniProt P63208 topology; general IHC practice).
| Which tissue and cell type should anchor interpretation? (HPA tissue IHC) | Breast glandular cells, bronchial respiratory epithelial cells and placental trophoblastic cells are High; cardiomyocytes and skeletal myocytes are Not detected (HPA tissue IHC). Evaluate named cells within their tissue context rather than treating every cell in a section as an equivalent reference (general IHC practice). |
| How firm is the tissue-pattern evidence? (HPA tissue IHC) | HPA rates tissue IHC Approved, with medium consistency between staining and RNA and external verification pending (HPA tissue IHC). Its low tissue-specificity RNA classification does not mean every cell has equal protein staining (HPA tissue IHC: RNA specificity and cell-level staining). |
| What does protein topology contribute? (UniProt P63208) | SKP1 has no annotated transmembrane segment, signal peptide or propeptide; its annotated chain spans residues 2–163 (UniProt P63208 topology and processing). These features support scrutiny of a membrane-only pattern but do not predict antigen-retrieval conditions (UniProt P63208; general IHC practice). |
| Can isoforms or modifications explain an unusual slide? (UniProt P63208) | Two isoforms and a modified threonine at residue 131 are listed (UniProt P63208). The supplied record gives no antibody epitope or isoform-specific IHC pattern, so an unusual stain cannot be assigned to either feature (UniProt P63208; evidence limit). |
| Does IF/ICC show the same localisation? (HPA subcellular ICC-IF) | IF/ICC reports approved nucleoplasm and cytosol localisation, plus approved centrosome, cytokinetic bridge, primary cilium and basal body localisation (HPA subcellular ICC-IF). HPA cautions that these findings are based on antibodies targeting proteins from multiple genes; the extra structures are not an expected chromogenic tissue-IHC scoring criterion (HPA subcellular ICC-IF; HPA tissue IHC). |
| What does antibody validation establish? (HPA antibodies) | CAB012982 is Approved for IHC, while HPA053745 is Approved for ICC and has no listed IHC status (HPA antibodies). Those application statuses should be kept distinct when comparing a tissue section with IF/ICC images (HPA antibodies; general IHC practice). |
| Situation | Likely cause | Next action |
|---|---|---|
| Positive-reference cells show no chromogenic signal (HPA tissue IHC: High in breast glandular cells). | An unsuccessful staining or detection step is possible; the HPA tissue level alone does not establish why the run failed (general IHC practice; HPA tissue IHC). | Confirm tissue identity and morphology, inspect run controls, and repeat using the catalog antibody's IHC-P instructions if needed (general IHC practice). |
| Only membrane-edge staining is visible (HPA tissue IHC: cytoplasmic and nuclear pattern). | This conflicts with the reported pattern and absent transmembrane segment; edge artefact is possible (HPA tissue IHC; UniProt P63208 topology; general IHC practice). | Compare internal cells with section edges and check reagent controls before scoring the signal (general IHC practice). |
| A Not detected cell type stains strongly (HPA tissue IHC: cardiomyocytes and skeletal myocytes). | Cross-reactivity or endogenous detection activity is possible; neither is established by the HPA result alone (HPA tissue IHC; general IHC practice). | Compare a reagent control and an HPA High cell type on a suitable section; score the named cell populations separately (HPA tissue IHC; general IHC practice). |
| Diffuse colour makes nuclei and cytoplasm hard to distinguish (general IHC practice). | Background from detection reagents or blocking conditions is possible (general IHC practice). | Inspect negative controls and counterstain, then optimise blocking, detection and wash conditions as general IHC workflow variables (general IHC practice). |
| Weak staining occurs in a proposed low-signal reference (HPA tissue IHC: Low in alveolar cells or hepatocytes). | The selected cells may have low reported protein staining, so weak signal is not by itself a failed run (HPA tissue IHC). | Include an HPA High cell type for the run-level comparison and interpret the low-signal cells in context (HPA tissue IHC; general IHC practice). |
| Changing retrieval appears to alter the result (general IHC practice). | Target-specific fixation effects are not established by the supplied assay evidence. Verify with a matched IHC source before attributing a result to fixation. | Record the retrieval conditions and compare matched sections with the same positive reference and controls; avoid attributing the change to an established SKP1 fixation effect (general IHC practice). |
Experiment evidence
IHC & IF images showing SKP1 staining
A00476-2 · IHCIHC analysis of SKP1 using anti-SKP1 antibody (A00476-2). SKP1 was detected in a paraffin-embedded section of human breast cancer tissue. He
A00476-2 · IHCIHC analysis of SKP1 using anti-SKP1 antibody (A00476-2). SKP1 was detected in a paraffin-embedded section of human brain tissue. Heat media
A00476-2 · IFIF analysis of SKP1 using anti-SKP1 antibody (A00476-2) and anti-Tubulin Alpha antibody (M03989-3). SKP1 was detected in immunocytochemical
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000113558-SKP1/tissue/cerebral+cortex#imid_3553764
HPA · CerebellumHuman Protein Atlas IHC, Cerebellum. Source: https://www.proteinatlas.org/ENSG00000113558-SKP1/tissue/cerebellum#imid_3553767
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000113558-SKP1/tissue/colon#imid_3553698
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000113558-SKP1/tissue/liver#imid_3553699
HPA · ICC-IF MCF-7Human Protein Atlas immunofluorescence, MCF-7, antibody HPA053745; green = SKP1, blue = nucleus, red = microtubules.
HPA · ICC-IF MCF-7Human Protein Atlas immunofluorescence, MCF-7, antibody HPA053745; green = SKP1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SKP1 IHC & IF
🧪Run breast first: glandular cells should stain (HPA: breast glandular cells, High). Use appendix glandular cells as the negative tissue (HPA: Not detected); on the breast slide, cells judged negative should show counterstain without DAB signal, although the supplied HPA row does not identify a specific internal negative cell type (HPA: breast glandular cells, High).
Positive control tissue: Breast (Glandular cells, HPA High)
Negative control tissue: Appendix (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SKP1 in MCF-7, PC-3, ASC52telo, RPTEC/TERT1, hTERT-RPE1 (serum starved), KOLF2.1J, with annotated localisation: Nucleoplasm (approved), Cytosol (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control; a host- and isotype-matched rabbit IgG control where applicable; and SKP1-knockout material or antigen-peptide competition if available (caption: rabbit primary; standard IHC practice). Quench endogenous peroxidase and check blood-rich areas of the breast section for background before scoring glandular staining (standard chromogenic IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected paraffin-section caption does not state the fixative (A00476-2 caption). The caption uses heat retrieval in EDTA at pH 8.0, but does not establish that retrieval is required (A00476-2 caption). No frozen-section evidence establishes an easier route; HPA ICC-IF images provide an IF localization reference, while blood-associated peroxidase remains a potential artefact in breast IHC (HPA: subcellular ICC-IF; standard chromogenic IHC practice).
HPA tissue IHC evidence for SKP1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium consistency between antibody staining and RNA expression data. Pending external verification.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Breast | Glandular cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | Not detected | Protein (IHC) | HPA → |
| Skeletal muscle | Myocytes | Not detected | Protein (IHC) | HPA → |
| Smooth muscle | Smooth muscle cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SKP1 IHC Tips
Troubleshoot SKP1 staining in paraffin sections by controlling retrieval and detection, then assessing signal by cell type and compartment.
How should I adjust retrieval when SKP1 staining is weak or diffuse?
Start with heat-mediated EDTA retrieval at pH 8.0 for paraffin sections (datasheet A00476-2). The illustrated section used 2 μg/ml primary antibody overnight at 4°C after 10% goat-serum blocking, so hold those conditions constant while assessing retrieval (caption A00476-2). If staining is weak, compare shorter and longer heating intervals on adjacent sections while keeping cooling and detection identical; try citrate buffer only as a fallback (standard IHC practice). Check for tissue lifting, lost nuclear detail, and diffuse DAB after heating (standard IHC practice). Score nuclear and cytoplasmic signal separately because both occur in tissues (HPA tissue IHC).
Can fixation explain inconsistent SKP1 staining between paraffin blocks?
Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative (caption A00476-2). Record each block’s fixative, fixation duration, tissue thickness, and processing history before comparing SKP1 intensity (standard IHC practice). Test sections from differently processed blocks in the same staining run, with the same pH 8.0 EDTA retrieval and detection settings (datasheet A00476-2; standard IHC practice). Assess morphology alongside staining, since poor preservation can undermine compartment scoring (standard IHC practice). Do not infer a fixation effect from tissue-expression patterns or SKP1 topology; neither supplies target-specific fixation evidence (HPA tissue IHC; UniProt P63208 topology).
Should SKP1 stain nuclei, cytoplasm, or both in tissue sections?
Assess both nuclear and cytoplasmic DAB staining: expression in both compartments is reported across most tissues (HPA tissue IHC). Nucleoplasm and cytosol are the approved main locations in cell imaging, supporting separate compartment assessment (HPA subcellular). Additional centrosome, cytokinetic-bridge, primary-cilium, and basal-body locations are reported, but the source cautions that these findings involve antibodies targeting proteins from multiple genes (HPA subcellular). Do not call a small DAB punctum one of those structures from routine sections alone; correlate with morphology and a suitable compartment marker (standard IHC practice). Compare the same cell type across sections before interpreting a shift in nuclear-to-cytoplasmic staining (standard IHC practice).
Could isoforms or epitope accessibility change my SKP1 IHC result?
SKP1 has 2 annotated isoforms, so confirm which sequence region the IHC-validated antibody recognizes before comparing specimens (UniProt P63208 isoforms). The annotated protein chain spans residues 2–163, with a reported phosphothreonine at residue 131 (UniProt P63208 processing; modified residues). These annotations do not establish whether this antibody distinguishes isoforms or whether phosphorylation changes binding; obtain its epitope information before making either claim (UniProt P63208; standard IHC practice). SKP1 has no annotated transmembrane segment or glycosylation sites, but neither fact establishes epitope accessibility in processed sections (UniProt P63208 topology; glycosylation). Compare staining against an independent antibody with a documented epitope when specificity remains uncertain (standard IHC practice).
How can I check SKP1 localisation by IF alongside tissue IHC?
Use IF as a complementary localisation check: nucleoplasm and cytosol are the approved main locations in cell imaging (HPA subcellular). In breast tissue, multiplex SKP1 with an epithelial marker to identify glandular cells, which show high IHC staining in the reference profile (HPA tissue IHC; standard IF practice). Choose a red or far-red SKP1 fluorophore after checking tissue autofluorescence in each channel, and include single-label controls to assess bleed-through (standard IF practice). SKP1 has no transmembrane segment, so use controlled permeabilisation for access to cytosolic and nuclear epitopes while checking cell morphology (UniProt P63208 topology; HPA subcellular; standard IF practice). Keep IF conclusions distinct from the paraffin-section DAB result (caption A00476-2; standard IHC practice).
What should I change when DAB background obscures SKP1 staining?
First inspect a no-primary section for signal from the detection reagents, tissue pigment, or endogenous peroxidase (standard IHC practice). The illustrated assay used 10% goat-serum blocking, 2 μg/ml primary antibody overnight at 4°C, and a peroxidase-linked secondary before DAB development (caption A00476-2). Recheck the peroxidase block, washing, secondary exposure, and DAB development time when background persists (standard IHC practice). Titrate the primary on adjacent sections while retaining a known staining reference and identical retrieval conditions (standard IHC practice). Interpret faint diffuse colour cautiously because SKP1 is reported in both nuclear and cytoplasmic compartments across most tissues (HPA tissue IHC).
How should I quantify SKP1 IHC across specimens? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and scoring threshold before reviewing specimen groups, then score nuclear and cytoplasmic DAB separately (standard IHC practice; HPA tissue IHC). For each compartment, record the percentage of positive cells and an H-score from 0–300, calculated from the percentages at intensity grades 0–3 (standard IHC practice). Normalise counts to the number of evaluable cells in the same cell type; use positive-cell density per mm² only when area is the relevant denominator (standard IHC practice). Exclude folds, necrosis, and section edges using consistent rules (standard IHC practice). Keep retrieval, DAB development, imaging, and thresholds consistent across runs, and include a reference section to track drift (standard IHC practice).
How do I distinguish genuine SKP1 staining from artefact?
Look for reproducible nuclear and cytoplasmic staining in intact cells, the broad pattern reported for SKP1 tissue IHC (HPA tissue IHC). Breast glandular cells provide a reported high-staining reference, while cardiomyocytes are reported as not detected; these are comparisons, not absolute specificity controls (HPA tissue IHC). Treat colour concentrated at section edges, folds, or necrotic regions as suspect and compare it with adjacent intact tissue (standard IHC practice). A no-primary control helps reveal endogenous enzyme activity or detection background, while an independent antibody can strengthen a specificity assessment (standard IHC practice). The tissue profile is approved but has medium staining-to-RNA consistency and awaits external verification, so interpret unexpected patterns cautiously (HPA tissue IHC).
Boster reagents
Best SKP1 / S-phase kinase-associated protein 1 IHC Antibodies
A00476-2 has IHC images from human paraffin sections and an IF image from HeLa cells; both listed antibodies report human, mouse and rat reactivity (catalog image captions; catalog reactivity).
Real IHC data
Anti-SKP1 Antibody ®
Cat # A00476-2
A00476-2 is listed for IHC and IF, with images from human paraffin sections of breast cancer and brain tissue and IF staining of HeLa cells (catalog applications; catalog image captions). M00476 is listed for IF/ICC, with human, mouse and rat reactivity, but no IHC or IF image is supplied (catalog applications; catalog reactivity; catalog image captions).
Which to pick: Choose A00476-2 for tissue IHC: its own images show human paraffin sections after EDTA pH 8.0 heat retrieval, with the fixative unreported (A00476-2 IHC captions). For IF/ICC, A00476-2 has a HeLa IF image; M00476 is a monoclonal option listed for IF/ICC without a supplied image (A00476-2 IF caption; M00476 clone and applications). Both list human, mouse and rat reactivity, while the supplied IHC and IF images show human samples only (catalog reactivity; catalog image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P63208 (SKP1_HUMAN, S-phase kinase-associated protein 1).
- Human Protein Atlas. SKP1 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. SKP1 subcellular location (ICC-IF): Mainly localized to the nucleoplasm and cytosol. In addition localized to the centrosome, cytokinetic bridge, primary cilium and basal body. Caution: Based on antibodies targeting proteins from multiple genes..
- Human Protein Atlas. SKP1 antibody validation summary (2 antibodies).
- Skp1 in lung cancer: clinical significance and therapeutic efficacy of its small molecule inhibitors. Oncotarget 2015 — PMC4741501.
- Transcriptional Profiling Reveals the Regulatory Role of DNER in Promoting Pancreatic Neuroendocrine Neoplasms. Frontiers in genetics 2020 — PMC7728999.
- Dysregulation of core components of SCF complex in poly-glutamine disorders. Cell death & disease 2012 — PMC3542602.
- Inhibition of SCF(KDM2A)/USP22-dependent nuclear β-catenin ubiquitylation mediates cerebral ischemic tolerance. Communications biology 2025 — PMC11814243.
- PubMed PMID:7553852 — UniProt-cited evidence.
- PubMed PMID:8530064 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SKP1 (S-phase kinase-associated protein 1). Expected localisation Cytoplasmic and nuclear staining in most tissues (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A00476-2). Validated IHC antibody: A00476-2 at 2-5μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Breast (Glandular cells); negative Appendix. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet A00476-2); 2. Fixation: Image fixative and duration unreported (datasheet A00476-2); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet A00476-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A00476-2); 8. Primary antibody: Rabbit anti-SKP1, 2-5μg/ml (datasheet A00476-2); 9. Primary incubation: Overnight at 4 °C (datasheet A00476-2). Watch for: Fixation: Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific); Caveat: Cell-type intensity varies across tissues (HPA tissue IHC); Isoform / epitope: 2 isoforms; epitope coverage is unspecified (UniProt); Regulation: No expression regulator specified (UniProt). Evidence: UniProt P63208, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoplasm and cytosol. In addition…, Datasheet A00476-2, PMC4741501, PMC7728999. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SKP1/immunohistochemistry-ihc-guide.