This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
KPNA2 / Importin subunit alpha-1 · IHC design guide
Design Immunohistochemistry for KPNA2
Plan KPNA2 chromogenic IHC on paraffin sections around nuclear staining in cell subsets (HPA tissue IHC). Use testis pachytene spermatocytes or lymph node germinal center cells as positive controls (HPA tissue IHC), and score nuclei by cell type.
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 | Nuclear staining in tissue (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in subsets of cells in most tissues (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 | Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Staining varies by cell type; score nuclei separately (HPA tissue IHC) | |
| Regulation | High in testis pachytene spermatocytes (HPA tissue IHC) | |
| Isoform / epitope | No isoforms listed; mature chain spans residues 2–529 (UniProt) |
Section 1
Recommended KPNA2 IHC & IF Protocols
The catalog antibody’s IHC protocol (datasheet: A01776-3) is accompanied by four published KPNA2 tissue-staining protocols (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 retrieval at pH 8.0 for the catalog antibody (datasheet: A01776-3); published retrieval conditions used citrate at pH 6.0 or solution at pH 9.0 (PMC7661224; PMC9808660).
Section 2
What Is the Expected KPNA2 Staining Pattern?
KPNA2 is mainly nuclear in subsets of cells across most tissues (HPA tissue IHC: Enhanced). Its supported nucleoplasmic location has an additional cytosolic component (HPA ICC-IF: supported); UniProt also lists nucleus and cytoplasm, and reports no transmembrane segment (UniProt P52292 topology). Expect the clearest IHC signal in the specific cells HPA rates High, while assessing both compartment and cell identity.
| Strong nuclear staining in germinal center cells, pachytene spermatocytes, or cardiomyocytes. | This fits the reported High staining in those cells (HPA tissue IHC). Score nuclei within the named cell population, since the broader tissue can contain cells with different staining; KPNA2 is reported in subsets of cells in most tissues (HPA tissue IHC). |
| Signal is mainly at cell borders or appears as an exclusive membranous pattern, with little nuclear staining. | Reassess specificity and slide interpretation: the expected tissue pattern is nuclear (HPA tissue IHC), and KPNA2 has no transmembrane segment (UniProt P52292 topology). Some cytosolic signal alone is compatible with the supported ICC-IF location (HPA ICC-IF); do not classify every nonnuclear pixel as artefact. |
| Strong staining appears in adipocytes or prostate glandular cells while expected positive nuclei also stain. | Those cell types were Not detected in the sampled HPA tissue IHC images (HPA tissue IHC). Consider cross-reactivity or endogenous chromogenic activity (standard IHC practice), then compare cell morphology and controls. A Not detected observation is a context-specific reference, not proof that every such cell must be negative. |
| Color spreads across tissue and empty areas, obscuring nuclear boundaries. | Treat the diffuse deposit as background until controls resolve it (standard IHC practice). Check blocking, washes, chromogen development, and a no-primary control (standard IHC practice); the reported KPNA2 tissue pattern is nuclear in subsets of cells (HPA tissue IHC). |
| No nuclear signal appears in an otherwise evaluable known-positive section. | First confirm that the relevant cells are present: HPA rates germinal center cells in lymph node and tonsil, and pachytene spermatocytes in testis, High (HPA tissue IHC). If they are present, review the IHC antibody, retrieval, detection, and run controls (standard IHC practice). |
💡Expected KPNA2 appearanceCall a result positive when identifiable cells show distinct nuclear staining, potentially with lesser cytosolic signal (HPA tissue IHC; HPA ICC-IF), especially in HPA High cell populations (HPA tissue IHC); broad diffuse color or exclusive membrane-edge staining warrants investigation (standard IHC practice; UniProt P52292 topology).
| Cell population and reference tissue | Choose a reference with identifiable High cells, such as lymph-node germinal center cells or testis pachytene spermatocytes (HPA tissue IHC). HPA reports nuclear expression in subsets of cells in most tissues, so assess the named cells rather than averaging color across a section (HPA tissue IHC). |
| Strength of the IHC reference | The HPA tissue profile has Enhanced reliability, described as high consistency between antibody staining and RNA expression data (HPA tissue IHC). HPA041270 and CAB015460 each have Enhanced IHC validation (HPA antibodies). This supports the reference pattern, but does not establish performance for an unlisted antibody. |
| Antigen retrieval and assay conditions | Retrieval and detection conditions can be checked when IHC staining fails (standard IHC practice). The supplied UniProt and HPA records provide no KPNA2-specific retrieval condition or fixation-sensitivity result; avoid attributing a weak section to a particular fixation effect. |
| Endogenous chromogenic activity | Endogenous enzyme activity or nonspecific reagent binding can create color unrelated to the primary antibody (standard IHC practice). Use a no-primary control and an appropriate blocking step to interpret unexpected deposits (standard IHC practice); HPA cell-level staining alone cannot identify their cause. |
| IF/ICC Q&A: What location should fluorescence show? | Mainly nucleoplasm, with additional cytosol (HPA ICC-IF: supported). This cross-check helps interpret compartment, while the present decision criteria concern chromogenic IHC in paraffin sections (HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Known-positive nuclei are blank. | The selected field may lack the named positive cells, or an IHC staining step may have failed (HPA tissue IHC; standard IHC practice). | Locate HPA High cells in the section, then verify the primary-antibody, retrieval, and detection steps against the assay instructions and controls (HPA tissue IHC; standard IHC practice). |
| Only cytoplasmic color is apparent in a presumed positive population. | KPNA2 can have a cytosolic component, but HPA describes the main supported ICC-IF location as nucleoplasm (HPA ICC-IF). | Inspect counterstained nuclei and a positive control before accepting the result; investigate absent nuclear staining with assay controls (standard IHC practice; HPA tissue IHC). |
| Membrane-edge staining dominates. | The pattern conflicts with nuclear tissue staining and the absence of a transmembrane segment (HPA tissue IHC; UniProt P52292 topology). | Compare with a no-primary control and review cell boundaries, chromogen deposit, and antibody specificity (standard IHC practice). |
| Adipocytes or prostate glandular cells stain strongly. | HPA lists those sampled cell populations as Not detected; cross-reactivity or endogenous detection activity is possible (HPA tissue IHC; standard IHC practice). | Check a no-primary control and compare staining with nearby expected positive cells; treat a mismatch as a reason to validate, not an automatic diagnosis of artefact (standard IHC practice; HPA tissue IHC). |
| Diffuse color makes nuclei hard to score. | Background from nonspecific binding, incomplete washing, or excessive chromogen development can obscure compartment boundaries (standard IHC practice). | Review blocking, washes, development, and the no-primary control; score only clearly resolved cellular staining (standard IHC practice). |
| Two sections show different proportions of positive cells. | KPNA2 is reported in subsets of cells in most tissues, and HPA staining levels refer to specific cell types (HPA tissue IHC). | Compare matching cell populations and record their nuclear staining separately from whole-section intensity (HPA tissue IHC; standard IHC practice). |
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 score nuclear staining in pachytene spermatocytes, where KPNA2 is High (HPA: testis, pachytene spermatocytes). Use adipose tissue as the negative tissue, focusing on adipocytes where KPNA2 is Not detected (HPA: adipose tissue, adipocytes); on the testis slide, use cells outside the pachytene spermatocyte population as background comparators only when their DAB signal is at no-primary background, since HPA does not establish them as KPNA2-negative (HPA: testis, pachytene spermatocytes).
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 a no-primary, secondary-only slide, concentration-matched nonimmune rabbit IgG as an isotype control, and a matched KPNA2 knockout specimen or cognate peptide-blocking control if available (caption: rabbit anti-KPNA2; standard IHC controls). Block endogenous peroxidase before HRP/DAB detection and check the no-primary testis slide for residual signal (caption: HRP/DAB; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the exact A01776-3 testis caption does not state a fixative (caption: fixative unreported). That paraffin-section example used heat retrieval in EDTA, pH 8.0, so verify retrieval with the chosen specimen preparation; the caption does not establish that retrieval is universally required (caption: EDTA retrieval). Frozen-section or tissue-IF testing is not established as easier by the supplied evidence; HPA ICC-IF images support mainly nucleoplasmic with additional cytosolic localisation, while dense testicular germ-cell nuclei call for a light counterstain when scoring nuclear DAB (HPA: subcellular; standard IHC practice).
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 sections by checking retrieval, compartment, cell type, controls and scoring before interpreting chromogenic signal.
Which retrieval conditions should I try first for weak KPNA2 staining?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A01776-3). The catalog antibody’s rat testis IHC image used that buffer, followed by 10% goat serum and 2 μg/ml primary antibody overnight at 4°C (datasheet A01776-3). If staining is weak, compare retrieval heating and cooling conditions on adjacent sections while holding antibody concentration and detection constant (standard IHC practice). Check whether nuclear staining in the expected cell population improves without a parallel rise in diffuse background; HPA reports nuclear expression in subsets of cells in most tissues (HPA tissue IHC).
Could fixation be masking KPNA2 in my paraffin sections?
The selected rat testis IHC caption identifies a paraffin section but does not state its fixative, so KPNA2-specific fixation sensitivity is unknown (datasheet A01776-3). Record the actual fixative, fixation duration and tissue thickness for each specimen, then compare similarly processed sections using the same EDTA pH 8.0 retrieval (datasheet A01776-3; standard IHC practice). Excessive or inconsistent fixation can change epitope accessibility in paraffin IHC generally, but the supplied evidence does not establish a KPNA2-specific threshold (standard IHC practice). Include a section with expected nuclear staining to distinguish a processing problem from a genuinely low signal in the test sample (HPA tissue IHC; standard IHC practice).
How should I evaluate nuclear versus cytoplasmic KPNA2 staining?
Score nuclear and cytoplasmic staining separately because KPNA2 is reported in both compartments (UniProt P52292 subcellular location). The supported subcellular pattern is mainly nucleoplasmic with additional cytosolic signal, while tissue IHC reports nuclear expression in subsets of cells in most tissues (HPA subcellular; HPA tissue IHC). Compare staining with cell morphology and the counterstain at the same magnification, and inspect adjacent sections when boundaries are unclear (standard IHC practice). Treat a solely membrane-like pattern cautiously: UniProt lists ER and Golgi membrane locations but reports no transmembrane segment, and its ER/Golgi retention note is specific to interaction with SARS-COV ORF6 (UniProt P52292 subcellular location and topology).
Can isoforms or epitope position explain inconsistent KPNA2 staining?
The supplied UniProt record lists 0 isoforms and an importin-beta-binding domain at residues 2–60, so there is no documented isoform switch here to explain a changed IHC pattern (UniProt P52292 isoforms and domains). The record also lists acetylation at residue 2 and phosphorylation at residues 62 and 490, without showing that these modifications affect this antibody’s binding (UniProt P52292 modified residues). Ask for the antibody’s immunogen or mapped epitope before assigning an epitope-based cause; neither is supplied in the selected caption (datasheet A01776-3). Compare retrieval conditions on adjacent sections and use an independent, validated reagent if epitope accessibility remains a concern (standard IHC practice).
How can I check a KPNA2 pattern by multiplex IF?
Use IF as a separate assay and first establish that the chosen antibody works under its IF conditions; the selected product evidence documents paraffin-section chromogenic IHC (datasheet A01776-3). Pair KPNA2 with a marker for the cell population under study, using separate fluorophore channels to test whether signal belongs to the expected cells (standard IF practice). Choose a fluorophore channel after checking tissue autofluorescence and include single-label controls to assess bleed-through (standard IF practice). For intracellular nuclear and cytosolic epitopes, assess permeabilisation after fixation and compare compartment patterns with the supported nucleoplasmic and additional cytosolic locations (HPA subcellular; standard IF practice).
What should I change when KPNA2 DAB staining is diffuse?
Inspect a no-primary control to identify detection-system staining, and check the peroxidase block before interpreting diffuse DAB signal (standard chromogenic IHC practice). The selected caption used peroxidase-conjugated secondary detection and DAB, with 10% goat serum blocking and 2 μg/ml primary antibody overnight at 4°C (datasheet A01776-3). If background rises broadly, compare primary concentration, blocking and wash conditions on adjacent sections while keeping retrieval constant at EDTA pH 8.0 (datasheet A01776-3; standard IHC practice). Examine section edges, damaged areas and precipitate separately from intact cells, and require a plausible nuclear or cytosolic distribution before calling signal KPNA2 (HPA subcellular; standard IHC practice).
How should I quantify KPNA2 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the tissue region and cell population before scoring, because HPA reports nuclear expression in subsets of cells rather than uniform staining throughout most tissues (HPA tissue IHC). Record nuclear percent-positive cells and intensity, then calculate an H-score where appropriate; report cytoplasmic staining separately using the same prespecified thresholds (HPA tissue IHC; standard IHC practice). Normalise cell-based results to the number of evaluable cells in the defined population, or report positive-cell density per mm² of viable tissue (standard IHC practice). Keep retrieval, imaging, counterstain and scoring criteria consistent across specimens, and exclude folds, necrosis and section edges from the analysed area (standard IHC practice).
When is a KPNA2-positive IHC result convincing?
A convincing result shows staining within intact cells in a plausible compartment, with nuclear signal in the relevant cell subset and possible cytosolic signal (HPA tissue IHC; HPA subcellular). For example, HPA reports high staining in testis pachytene spermatocytes and lymph-node germinal center cells, whereas adipocytes are listed as not detected (HPA tissue IHC). Check whether apparent positivity instead follows section edges, necrotic areas or DAB deposits, and review a no-primary control for endogenous-enzyme or detection background (standard chromogenic IHC practice). Interpret a membrane-only pattern cautiously because KPNA2 lacks a transmembrane segment, even though UniProt also lists ER and Golgi membrane locations (UniProt P52292 topology and subcellular location).
Boster reagents
Best KPNA2 / Importin subunit alpha-1 IHC Antibodies
Two anti-KPNA2 antibodies have IHC images from human heart, human tumors, and rat testis; one also has an IF image from human heart (catalog 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 captions). A01776 has IHC and IF images from human heart (A01776 image captions).
Which to pick: For paraffin-section IHC, choose A01776-3: its captions document EDTA retrieval at pH 8.0 and primary antibody at 2 μg/ml; the fixative is unreported (A01776-3 IHC captions). For IF, choose A01776, which lists IF and shows staining in human heart at 20 μg/mL; ICC is not listed (A01776 applications and IF caption). Both list human, mouse, and rat reactivity, while the supplied IHC images show human and rat for A01776-3 and human for A01776 (catalog reactivity; IHC captions).
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 Nuclear staining in tissue (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: Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific); Caveat: Staining varies by cell type; score nuclei separately (HPA tissue IHC); Isoform / epitope: No isoforms listed; mature chain spans residues 2–529 (UniProt); Regulation: High in testis pachytene spermatocytes (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.