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KPNA2 / Importin subunit alpha-1 · IHC design guide
Design Immunohistochemistry for KPNA2
Plan chromogenic KPNA2 IHC in paraffin sections using the nuclear staining seen in cell subsets across most tissues (HPA tissue IHC). The guide identifies positive tissue controls and an IHC-validated antibody condition of 2 μg/mL (HPA tissue IHC; datasheet A01776-3).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
KPNA2 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 | Nuclei in cell subsets (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in subsets, including germinal center cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A01776-3) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A01776-3) | |
| Caveat | Cells within a positive tissue may lack staining (HPA tissue IHC) | |
| Regulation | Cell-subset expression varies by tissue (HPA tissue IHC) | |
| Isoform / epitope | No annotated isoforms; mature chain is 2–529 (UniProt) |
Section 1
Recommended KPNA2 IHC & IF Protocols
The catalog antibody protocol uses EDTA pH 8.0 retrieval (datasheet A01776-3). These published IHC protocols provide tissue-specific alternatives (PMC7661224; PMC5403343; PMC9808660; PMC9385962).
| Sample | Paraffin-embedded rat testis tissue; fixative not specified (datasheet A01776-3) |
| Fixation | Image fixative and duration unreported (datasheet A01776-3); 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 A01776-3); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01776-3) |
| Primary antibody | Rabbit anti-KPNA2, 2-5 μg/ml (datasheet A01776-3) |
| Primary incubation | Overnight at 4 °C (datasheet A01776-3) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A01776-3) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | KPNA2-positive staining in lymphoid tissue of appendix (HPA tissue IHC: High). HPA tissue profile: Nuclear expression in subsets of cells in most tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 for the catalog antibody (datasheet A01776-3); assess the published retrieval conditions when adapting another antibody or tissue protocol (PMC7661224; PMC9808660).
Section 2
What Is the Expected KPNA2 Staining Pattern?
KPNA2 should stain nuclei in subsets of cells across most tissues, with nucleoplasm as the principal location and some cytosolic signal possible (HPA tissue IHC; HPA subcellular). Strong examples include testis pachytene spermatocytes and lymph node germinal center cells (HPA: High). The tissue IHC profile has Enhanced reliability (HPA tissue IHC). KPNA2 has no transmembrane segment (UniProt P52292 topology).
| Distinct nuclear staining in pachytene spermatocytes or germinal center cells, with nearby cells less stained. | This fits the subset pattern and High staining reported for these cells (HPA tissue IHC). Assess cell identity and nuclear location together; intensity alone cannot establish specificity (general IHC practice). |
| Predominantly extracellular or sharply continuous cell membrane staining, with little nuclear staining. | That distribution conflicts with the principal nucleoplasmic location (HPA subcellular) and lack of a transmembrane segment (UniProt P52292 topology). Consider artefact. Some cytosolic staining can be genuine (HPA subcellular). |
| Strong staining of adipocytes or prostate glandular cells while the intended positive cells are unstained. | Both cell types are reported as Not detected (HPA tissue IHC). Review cross-reactivity or endogenous chromogenic activity (general IHC practice), then compare the suspect staining with an appropriate negative control. |
| Uniform haze covers nuclei, cytoplasm, and spaces between cells. | Diffuse background obscures the expected subset-restricted nuclear pattern (HPA tissue IHC). Check blocking, washing, and chromogen development with negative controls (general IHC practice); haze alone cannot locate KPNA2. |
| No staining appears in testis pachytene spermatocytes or tonsil germinal center cells. | These are High examples (HPA tissue IHC). A blank result there calls for a run-level check of section integrity, detection, and the antibody's IHC-P conditions (general IHC practice) before interpreting other tissues as negative. |
💡Expected KPNA2 appearanceCall a result positive when identifiable cells show distinct nuclear staining, preferably strong in an HPA High cell population; diffuse haze or dominant extracellular or membrane staining is suspect (HPA tissue IHC; HPA subcellular; UniProt P52292 topology; general IHC practice).
| Tissue and cell selection | KPNA2 is ubiquitous at the expression level (UniProt P52292), yet nuclear IHC staining occurs in subsets of cells (HPA tissue IHC). Choose a documented High population, such as testis pachytene spermatocytes, for the positive control (HPA: High). |
| Antibody validation | HPA041270 and CAB015460 each have Enhanced IHC validation (HPA antibodies). The tissue profile also reports Enhanced reliability through consistency with RNA expression (HPA tissue IHC). These support the expected pattern but do not validate every staining condition. |
| Compartment and IF/ICC Q&A | Where should IF/ICC signal appear? Mainly in the nucleoplasm, with additional cytosol (HPA subcellular). This is a location cross-check for interpreting IHC; IF/ICC conditions belong to its own guide. |
| Antigen retrieval and epitope | No KPNA2-specific retrieval condition or antibody epitope is supplied. Retrieval choice requires the catalog antibody's IHC-P instructions and local control results (general IHC practice); HPA staining levels do not establish retrieval sensitivity. |
| Detection background | Endogenous chromogenic activity can mimic cellular staining, and inadequate blocking or washing can raise background (general IHC practice). Use negative controls to distinguish these effects from the HPA nuclear subset pattern (HPA tissue IHC). |
| Processing and membrane interpretation | UniProt lists a chain spanning residues 2–529, no signal peptide or propeptide, and no transmembrane segment (UniProt P52292). These annotations give no basis to expect a shed extracellular stain or a continuous membrane pattern. |
| Situation | Likely cause | Next action |
|---|---|---|
| High-background slide with weak nuclear contrast | Blocking, washing, or chromogen development may be contributing background (general IHC practice). | Inspect a negative control, adjust those general workflow steps, and rescore only clearly identifiable nuclei against the subset pattern (HPA tissue IHC). |
| Nuclear signal absent in a documented High population | A failed detection run, unsuitable antibody conditions, or damaged section can produce a blank result (general IHC practice). | Check section integrity and detection controls, then follow the catalog antibody's IHC-P instructions. Use testis pachytene spermatocytes or tonsil germinal center cells as positive comparators (HPA: High). |
| Cytosolic signal accompanies convincing nuclear staining | Cytosol is an additional supported KPNA2 location (HPA subcellular). | Keep the nuclear pattern and cell identity central to the IHC call (HPA tissue IHC); compare controls before classifying the accompanying cytosol as background (general IHC practice). |
| Only continuous membrane or extracellular signal is visible | The distribution is discordant with principal nucleoplasmic localization (HPA subcellular) and the absence of a transmembrane segment (UniProt P52292 topology). | Review morphology and negative controls for nonspecific staining (general IHC practice); do not score that pattern alone as KPNA2 positive. |
| Strong signal appears in an HPA Not detected cell type | Cross-reactivity or endogenous chromogenic activity is possible (general IHC practice); HPA reports adipocytes and prostate glandular cells as Not detected (HPA tissue IHC). | Compare the same run's negative control and a documented positive population, then reassess whether staining follows cells, nuclei, and expected distribution (general IHC practice; HPA tissue IHC). |
| Different tissues give different fractions of positive cells | Nuclear expression occurs in subsets across most tissues; recorded cell-level intensities range from High to Not detected (HPA tissue IHC). | Identify the stained cell type before comparing fractions, and include a documented High control in each run (HPA tissue IHC; general IHC practice). Do not infer a KPNA2 fixation effect from tissue differences. |
Experiment evidence
IHC & IF images showing KPNA2 staining
A01776-3 · IHCIHC analysis of KPNA2 using anti-KPNA2 antibody (A01776-3). KPNA2 was detected in a paraffin-embedded section of rat testis tissue. Heat med
A01776-3 · IHCIHC analysis of KPNA2 using anti-KPNA2 antibody (A01776-3). KPNA2 was detected in a paraffin-embedded section of human adenocarcinoma of the
A01776 · IHCImmunohistochemistry of KPNA2 in human heart tissue with KPNA2 antibody at 5 μg/mL.
A01776 · IFImmunofluorescence of KPNA2 in human heart tissue with KPNA2 antibody at 20 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000182481-KPNA2/tissue/cerebral+cortex#imid_3924624
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000182481-KPNA2/tissue/colon#imid_3924566
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000182481-KPNA2/tissue/liver#imid_3924559
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000182481-KPNA2/tissue/kidney#imid_3924552
HPA · ICC-IF U-251MGHuman Protein Atlas immunofluorescence, U-251MG, antibody CAB015460; green = KPNA2, blue = nucleus, red = microtubules.
HPA · ICC-IF U-251MGHuman Protein Atlas immunofluorescence, U-251MG, antibody CAB015460; green = KPNA2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for KPNA2 IHC & IF
🧪Run testis first and expect staining in pachytene spermatocytes (HPA: High in pachytene spermatocytes). Use adipose tissue adipocytes as the negative reference (HPA: Not detected in adipocytes); on the testis slide, neighboring cells should show only background staining in the control sections, although HPA does not identify a specific testis cell type as KPNA2-negative.
Positive control tissue: Appendix (Lymphoid tissue, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show KPNA2 in U-251MG, U2OS, A-549, MCF-7, KOLF2.1J, HEK293, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include no-primary (secondary-only) and concentration-matched nonimmune rabbit IgG isotype controls, plus validated KPNA2 knockout material as a biological negative (caption: rabbit primary antibody). Quench endogenous peroxidase and check background in testis before interpreting DAB staining (caption: HRP/DAB detection in rat testis).
⚠️Feasibility: A target-specific fixation window is unreported, and the exact A01776-3 tissue-IHC caption does not state the fixative (caption: fixative unreported). The paraffin-section example uses heat retrieval in EDTA at pH 8.0, but it does not establish that retrieval is required (caption: rat testis IHC). Frozen sections cannot be judged easier from the supplied evidence; IF/ICC has localization images showing mainly nucleoplasmic and additional cytosolic signal, while testis IHC needs peroxidase background control (HPA: subcellular ICC-IF; caption: HRP/DAB detection).
HPA tissue IHC evidence for KPNA2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High consistency between antibody staining and RNA expression data.). 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 |
|---|---|---|---|---|
| Appendix | Lymphoid tissue | High | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | High | Protein (IHC) | HPA → |
| Lymph node | Germinal center cells | High | Protein (IHC) | HPA → |
| Testis | Pachytene spermatocytes | High | Protein (IHC) | HPA → |
| Tonsil | Germinal center cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Ovary | Follicle cells | Not detected | Protein (IHC) | HPA → |
| Prostate | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Smooth muscle | Smooth muscle cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced KPNA2 IHC Tips
Troubleshoot KPNA2 staining in paraffin section chromogenic IHC, using the selected antibody’s tissue image and the stated expression evidence as reference points.
What retrieval should I start with if KPNA2 staining is weak?
Start with heat mediated retrieval in EDTA at pH 8.0 (datasheet A01776-3). The selected antibody detected KPNA2 in a paraffin section of rat testis after that retrieval, followed by 2 μg/ml primary antibody overnight at 4°C (datasheet A01776-3). If staining is weak, check heating consistency and section retention before comparing an alternative retrieval buffer on matched sections (standard IHC practice). Keep antibody concentration, detection, and development conditions constant during that comparison so any change can be attributed to retrieval (standard IHC practice). Judge improvement in the expected cell population and nuclear compartment, rather than by stronger staining across the whole section (HPA tissue IHC; standard IHC practice).
Could fixation explain inconsistent KPNA2 staining between blocks?
The selected tissue caption identifies a paraffin section but does not report its fixative, so target specific fixation sensitivity is unknown (datasheet A01776-3). Record the fixative, time in fixative, block age, and processing history for each specimen before comparing staining (standard IHC practice). Compare similarly processed blocks on the same run with EDTA retrieval at pH 8.0 and the same antibody concentration (datasheet A01776-3; standard IHC practice). Include a tissue control containing an expected positive cell population, such as testis pachytene spermatocytes, to detect run failure (HPA tissue IHC). If only one processing group fails, investigate that group’s handling without assigning a KPNA2 specific fixation mechanism (standard IHC practice).
Should I accept cytoplasmic KPNA2 staining in a paraffin section?
Expect nuclear staining in subsets of cells across most tissues, while allowing a cytoplasmic component because KPNA2 also occurs in the cytoplasm (HPA tissue IHC; UniProt P52292 subcellular). The supported subcellular pattern is mainly nucleoplasmic with additional cytosolic localisation (HPA subcellular). Compare nuclear and cytoplasmic signal separately in the same identified cell population, and check whether the nuclear pattern remains visible after changing counterstain or development time (HPA subcellular; standard IHC practice). Uniform cytoplasmic colour across unrelated cell types should prompt checks of antibody concentration, washing, and detection background (standard IHC practice). Membrane staining warrants particular scrutiny: KPNA2 has no transmembrane segment, and its reported ER/Golgi retention has a specified viral interaction context (UniProt P52292 topology; UniProt P52292 subcellular).
Could epitope placement or protein modification explain variable staining?
The supplied record lists 0 isoforms and an importin beta binding domain at residues 2–60, but gives no mapped epitope for this antibody (UniProt P52292 isoforms; UniProt P52292 domains; datasheet A01776-3). It also lists N acetylserine at residue 2 and phosphoserines at residues 62 and 490 (UniProt P52292 modified residues). Those annotations identify possible questions about epitope access; they do not establish that any modification alters this antibody’s IHC signal (UniProt P52292 modified residues; standard IHC interpretation). If staining differs between samples, compare matched retrieval and antibody conditions before invoking an epitope effect (standard IHC practice). Request an epitope map or orthogonal validation if the biological conclusion depends on a specific modified region (standard IHC practice).
How can I investigate a discordant KPNA2 immunofluorescence result?
The selected antibody’s supplied image documents chromogenic staining in a paraffin tissue section; it provides no IF/ICC validation (datasheet A01776-3). For an IF comparison, pair KPNA2 with a marker that identifies the expected cell population, such as pachytene spermatocytes in testis, and inspect nuclear overlap alongside a DNA counterstain (HPA tissue IHC; standard IF practice). Choose a fluorophore channel with low tissue autofluorescence and inspect an unstained or no primary control in every acquisition channel (standard IF practice). Because the expected signal is nucleoplasmic with additional cytosolic localisation and KPNA2 lacks a transmembrane segment, assess permeabilisation for access to intracellular epitopes (HPA subcellular; UniProt P52292 topology; standard IF practice). Compare compartments within identified cells rather than equating total fluorescence with chromogenic IHC intensity (standard IF/IHC practice).
How do I distinguish diffuse brown background from KPNA2 staining?
The selected image used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, and DAB based peroxidase detection (datasheet A01776-3). Use those values as a reference for this antibody, while checking whether background increases with primary concentration or DAB development time (datasheet A01776-3; standard IHC practice). Include a no primary control and assess endogenous peroxidase blocking as general chromogenic workflow checks (standard IHC practice). Examine folds, section edges, and damaged areas separately from intact tissue because local trapping can mimic signal (standard IHC practice). A convincing result should retain a cell restricted nuclear pattern consistent with the reported KPNA2 tissue profile (HPA tissue IHC).
What is a defensible way to score KPNA2 IHC across specimens? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring: HPA reports nuclear expression in subsets of cells, including high staining in testis pachytene spermatocytes (HPA tissue IHC). Score nuclear intensity from 0–3 and calculate an H score from the percentage at each intensity, yielding 0–300, or report the percentage of positive cells (standard IHC practice). For spatial comparisons, report positive cell density per mm² of evaluable tissue (standard IHC practice). Normalise counts to the number of eligible nuclei or measured area within the same annotated cell population, and exclude folds and necrosis by a prespecified rule (standard IHC practice). Keep retrieval, imaging, and positivity thresholds consistent across batches and include a shared control section (standard IHC practice).
When is an apparent KPNA2 positive cell likely an artefact?
A true candidate positive should occur in an identifiable cell population and show the expected nuclear emphasis, with possible cytoplasmic signal (HPA tissue IHC; HPA subcellular). In testis, staining of pachytene spermatocytes has direct tissue profile support; colour confined to section edges or necrotic regions needs separate scrutiny (HPA tissue IHC; standard IHC practice). Check unexpected membrane dominant staining against the absence of a KPNA2 transmembrane segment, and assess widespread brown staining with a no primary and peroxidase control (UniProt P52292 topology; standard IHC practice). Compare staining in the same compartment and cell type across control and study sections, using identical DAB development and counterstain conditions (standard IHC practice). Treat a localisation shift as provisional until morphology, controls, and an independent detection approach support it (standard IHC practice).
Boster reagents
Best KPNA2 / Importin subunit alpha-1 IHC Antibodies
Two anti-KPNA2 antibodies have IHC images from rat testis, human tumors, and human heart; one also has a human-heart IF image (A01776-3 and A01776 image captions).
Real IHC data
Anti-KPNA2 Antibody ®
Cat # A01776-3
Real IHC data
Anti-Importin subunit alpha-1 KPNA2 Antibody
Cat # A01776
A01776-3 has paraffin-section IHC images from rat testis and human colon adenocarcinoma, lymphoma, and lung cancer (A01776-3 IHC image captions). A01776 has IHC and IF images from human heart (A01776 IHC and IF image captions).
Which to pick: Choose A01776-3 for paraffin-section IHC: its images document human and rat tissues using 2 μg/mL antibody after EDTA retrieval; the fixative is unreported (A01776-3 IHC image captions). Choose A01776 for tissue IF; its human-heart image supports IF, while ICC is unreported (A01776 IF image caption; A01776 applications). For cross-species IHC, A01776-3 has human and rat tissue images; both antibodies list Human, Mouse, and Rat reactivity, but mouse IHC evidence and clonality are unreported (A01776-3 IHC image captions; catalog reactivity and clone fields).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P52292 (IMA1_HUMAN, Importin subunit alpha-1).
- Human Protein Atlas. KPNA2 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. KPNA2 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
- Human Protein Atlas. KPNA2 antibody validation summary (2 antibodies).
- KPNA2 expression is a potential marker for differential diagnosis between osteosarcomas and other malignant bone tumor mimics. Diagnostic pathology 2020 — PMC7661224.
- Karyopherin alpha 2 expression is a novel diagnostic and prognostic factor for colorectal cancer. Oncology letters 2017 — PMC5403343.
- Expression of Karyopherin Alpha 2 and Karyopherin Beta 1 Correlate with Poor Prognosis in Gastric Cancer. Oncology 2022 — PMC9808660.
- Decreased Expression of Karyopherin-α 1 is Related to the Malignant Degree of Cervical Cancer and is Critical for the Proliferation of Hela Cells. Pathology oncology research : POR 2022 — PMC9385962.
- PubMed PMID:7754385 — UniProt-cited evidence.
- PubMed PMID:11735022 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for KPNA2 (Importin subunit alpha-1). Expected localisation Nuclei in cell subsets (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A01776-3). Validated IHC antibody: A01776-3 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Lymphoid tissue); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded rat testis tissue; fixative not specified (datasheet A01776-3); 2. Fixation: Image fixative and duration unreported (datasheet A01776-3); 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 A01776-3); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01776-3); 8. Primary antibody: Rabbit anti-KPNA2, 2-5 μg/ml (datasheet A01776-3); 9. Primary incubation: Overnight at 4 °C (datasheet A01776-3). Watch for: Fixation: Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A01776-3); Caveat: Cells within a positive tissue may lack staining (HPA tissue IHC); Isoform / epitope: No annotated isoforms; mature chain is 2–529 (UniProt); Regulation: Cell-subset expression varies by tissue (HPA tissue IHC). Evidence: UniProt P52292, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A01776-3, PMC7661224, PMC5403343. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/KPNA2/immunohistochemistry-ihc-guide.