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PPP2R5E / Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform · IHC design guide
Design Immunohistochemistry for PPP2R5E
Plan chromogenic PPP2R5E IHC around its general cytoplasmic tissue pattern (HPA tissue IHC). The catalog antibody’s IHC range is 2–5 μg/ml; pachytene spermatocytes stain strongly in testis (datasheet A07588-2; HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PPP2R5E 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 | General cytoplasmic tissue staining (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining; high in pachytene spermatocytes (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A07588-2) | |
| Positive control | Testis+4 more · see all | |
| Negative control | Cervix+3 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections (standard IHC practice; not target-specific) | |
| Caveat | Staining has medium consistency with RNA expression (HPA tissue IHC) | |
| Regulation | Expression regulation unreported (UniProt) | |
| Isoform / epitope | 3 isoforms; epitope coverage is unknown (UniProt) |
Section 1
Recommended PPP2R5E IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A07588-2) and one published FFPE protocol (PMC13478537) provide starting conditions for PPP2R5E staining.
| Sample | Paraffin-embedded human colon cancer tissue; fixative not specified (datasheet A07588-2) |
| Fixation | Image fixative and duration unreported (datasheet A07588-2); 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 A07588-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A07588-2) |
| Primary antibody | Rabbit anti-PPP2R5E, 2-5 μg/ml (datasheet A07588-2) |
| Primary incubation | Overnight at 4 °C (datasheet A07588-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A07588-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | PPP2R5E-positive staining in pachytene spermatocytes of testis (HPA tissue IHC: High). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval (datasheet A07588-2); the published protocol reports no retrieval condition (PMC13478537).
Section 2
What Is the Expected PPP2R5E Staining Pattern?
PPP2R5E should show predominantly cytoplasmic staining in paraffin-section IHC (UniProt Q16537: cytoplasm; HPA tissue IHC: general cytoplasmic expression). Pachytene spermatocytes in testis are a strong reference, while several glandular, neuronal, endothelial and hematopoietic cell populations show medium staining (HPA tissue IHC). HPA rates the tissue pattern Approved, with medium consistency between antibody staining and RNA expression (HPA tissue IHC). PPP2R5E has no transmembrane segment (UniProt Q16537 topology).
| Cytoplasmic staining is high in testis pachytene spermatocytes (HPA tissue IHC). | This matches the strongest listed tissue and cell population; judge localisation within those cells, alongside intensity (HPA tissue IHC; UniProt Q16537: cytoplasm). |
| Cytoplasmic staining is medium in adrenal or breast glandular cells, cortical neurons, or colon endothelium (HPA tissue IHC). | These are listed medium-staining populations. Compare like cell types rather than expecting every cell in a section to stain equally (HPA tissue IHC; standard IHC practice). |
| Signal is predominantly nuclear or confined to cell borders instead of cytoplasm. | That disagrees with the reported general cytoplasmic IHC pattern and UniProt localisation; review antibody specificity and detection controls before assigning it to PPP2R5E (HPA tissue IHC; UniProt Q16537; standard IHC practice). |
| Strong signal appears in esophageal squamous epithelium or splenic red-pulp cells. | HPA lists these populations as not detected. Check cell identity and detection controls; unexpected signal may reflect cross-reactivity or endogenous detection activity (HPA tissue IHC; standard IHC practice). |
| Color covers tissue and blank areas without a clear cellular pattern, or testis pachytene spermatocytes show no signal. | Widespread haze suggests background; absent signal in the high-staining reference population raises a run-performance question. Neither alone proves PPP2R5E is absent (HPA tissue IHC; standard IHC practice). |
💡Expected PPP2R5E appearanceA convincing positive is predominantly cytoplasmic, with high staining in testis pachytene spermatocytes; strong nuclear-only or cell-border-only signal, or equally strong staining in HPA not-detected populations, warrants review (HPA tissue IHC; UniProt Q16537).
| Tissue and cell selection | Testis pachytene spermatocytes are listed High; adrenal and breast glandular cells, cortical neurons, and colon endothelial cells are Medium. Use the named cell population when judging a section (HPA tissue IHC). |
| Compartment and topology | UniProt places PPP2R5E in cytoplasm and reports no transmembrane segment; HPA describes general cytoplasmic IHC expression. Membrane-restricted staining is therefore unexpected (UniProt Q16537; HPA tissue IHC). |
| Strength of IHC evidence | The tissue profile is Approved, with medium staining–RNA consistency; both listed antibodies have Approved IHC status. These ratings support comparison with the observed pattern, not certainty for every specimen (HPA tissue IHC; HPA antibodies). |
| Isoforms and modified residues | UniProt lists 3 isoforms and five modified residues. The payload does not map antibody epitopes to isoforms or modifications, so these annotations cannot predict staining differences (UniProt Q16537). |
| IF/ICC Q: where should signal appear? | A: HPA reports mainly cytosol, with additional staining in sperm mid piece and principal piece. This is IF/ICC localisation evidence, not an IHC staining score or protocol (HPA subcellular ICC-IF). |
| Situation | Likely cause | Next action |
|---|---|---|
| Testis reference section lacks signal in pachytene spermatocytes. | The listed High population is missing from the readout; the cause cannot be assigned from the HPA profile alone (HPA tissue IHC). | Confirm the cells are present, then check IHC run controls, antibody application, detection and chromogen development (standard IHC practice). |
| Cytoplasm is faint in an HPA Medium population. | Medium is an observed category, and the tissue profile has medium staining–RNA consistency; faintness alone is inconclusive (HPA tissue IHC). | Compare the same cell type with a run reference and inspect the counterstain before calling it absent (HPA tissue IHC; standard IHC practice). |
| Signal is predominantly nuclear or outlines membranes. | This conflicts with cytoplasmic localisation and the absence of a transmembrane segment (UniProt Q16537; HPA tissue IHC). | Review compartment boundaries, detection controls and antibody specificity; do not score the unexpected pattern as confirmed PPP2R5E (standard IHC practice). |
| A not-detected HPA population stains strongly. | HPA lists cervical glandular cells, esophageal squamous cells, splenic red-pulp cells and vaginal squamous cells as not detected; unexpected signal needs investigation (HPA tissue IHC). | Verify the cell population and compare appropriate negative detection controls for endogenous activity or nonspecific staining (standard IHC practice). |
| Diffuse chromogen obscures cell boundaries. | Poorly localized color is compatible with background, so its distribution cannot establish cytoplasmic PPP2R5E (standard IHC practice; HPA tissue IHC). | Inspect no-primary and detection controls, background across tissue and blank areas, and counterstain clarity before scoring cells (standard IHC practice). |
| Different regions of a section appear inconsistent. | HPA reports staining by named cell population, including different levels across tissues; a whole-section average can conceal the relevant cells (HPA tissue IHC). | Identify the listed cell type in each region and score its compartment and intensity separately, noting any regions that cannot be identified (HPA tissue IHC; standard IHC practice). |
Experiment evidence
IHC & IF images showing PPP2R5E staining
A07588-2 · IHCIHC analysis of PPP2R5E using anti-PPP2R5E antibody (A07588-2). PPP2R5E was detected in a paraffin-embedded section of human colon cancer ti
A07588-2 · IHCIHC analysis of PPP2R5E using anti-PPP2R5E antibody (A07588-2). PPP2R5E was detected in a paraffin-embedded section of human colon tissue. H
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000154001-PPP2R5E/tissue/cerebral+cortex#imid_19132451
HPA · StomachHuman Protein Atlas IHC, Stomach. Source: https://www.proteinatlas.org/ENSG00000154001-PPP2R5E/tissue/stomach+1#imid_19132367
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000154001-PPP2R5E/tissue/colon#imid_19132385
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000154001-PPP2R5E/tissue/liver#imid_19132386
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA006034; green = PPP2R5E, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA006034; green = PPP2R5E, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PPP2R5E IHC & IF
🧪Run testis first; pachytene spermatocytes should stain (HPA: High in pachytene spermatocytes). Use esophagus squamous epithelium as the negative tissue (HPA: Not detected); on the testis slide, cells without convincing target staining should remain at background, with cell identity checked by morphology rather than assumed from the HPA row.
Positive control tissue: Testis (Pachytene spermatocytes, HPA High)
Negative control tissue: Cervix (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PPP2R5E in A-431, U-251MG, U2OS, Sperm, with annotated localisation: Cytosol (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and a concentration-matched rabbit IgG isotype control alongside a PPP2R5E knockout specimen if available (selected tissue-IHC caption: rabbit primary; standard IHC controls). For chromogenic testis sections, block endogenous peroxidase and check for background before scoring DAB staining (selected tissue-IHC caption: HRP/DAB detection; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the fixative in the selected A07588-2 paraffin-section caption is unreported (selected tissue-IHC caption). The caption uses heat retrieval in EDTA at pH 8.0, but does not establish whether retrieval is required; the supplied evidence does not show that frozen sections or IF are easier (selected tissue-IHC caption). For IF/ICC, cytosolic staining is the main expected pattern, with additional sperm mid-piece and principal-piece localization; assess testis autofluorescence with an unstained section (HPA: subcellular localization; standard IF practice).
HPA tissue IHC evidence for PPP2R5E
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium 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 |
|---|---|---|---|---|
| Testis | Pachytene spermatocytes | High | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Breast | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Cervix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
| Spleen | Cells in red pulp | Not detected | Protein (IHC) | HPA → |
| Vagina | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced PPP2R5E IHC Tips
Troubleshoot PPP2R5E staining in paraffin sections by checking retrieval, cell type, cytoplasmic localisation and controls before comparing signal intensity.
What retrieval should I use when PPP2R5E staining is weak?
Start with heat-mediated retrieval in EDTA at pH 8.0 for the catalog antibody (datasheet A07588-2). The documented paraffin-section example used 2 μg/ml primary antibody overnight at 4°C, so first confirm that your retrieval and primary incubation match those conditions (datasheet A07588-2). If staining remains weak, compare a modest range of heating durations on adjacent sections while keeping antibody concentration and DAB development constant; the caption does not specify a heating duration (datasheet A07588-2). Assess preserved morphology alongside signal, because excessive heating can damage sections and make apparent gains in staining difficult to interpret (standard IHC practice). Include a positive-reference section in each comparison, such as testis with highly stained pachytene spermatocytes (HPA tissue IHC).
Can fixation explain weak PPP2R5E staining in paraffin sections?
The selected paraffin-section caption does not state the fixative, and target-specific sensitivity to fixation is unknown (datasheet A07588-2). Record the actual fixative, fixation interval and processing history for each specimen before attributing a weak result to antigen loss (standard IHC practice). Compare similarly processed sections while holding EDTA retrieval at pH 8.0 and primary incubation at 2 μg/ml overnight at 4°C, as documented for the catalog antibody (datasheet A07588-2). Check morphology and staining in an internal reference population before increasing antibody concentration, since tissue processing can change both epitope access and background (standard IHC practice). Do not infer a PPP2R5E fixation effect from its cytoplasmic annotation or tissue staining profile (UniProt Q16537; HPA tissue IHC).
Where should convincing PPP2R5E staining appear?
Assess cellular cytoplasm as the principal compartment: UniProt annotates PPP2R5E as cytoplasmic, and HPA reports general cytoplasmic tissue staining (UniProt Q16537; HPA tissue IHC). HPA also supports a mainly cytosolic subcellular location, so a predominantly nuclear or cell-surface DAB pattern deserves closer control review (HPA subcellular). The protein has no annotated transmembrane segment, which gives no basis for treating crisp membrane staining alone as its expected pattern (UniProt Q16537 topology). Judge the signal within identified cell populations, since HPA reports High staining in testicular pachytene spermatocytes but Medium staining in colonic endothelial cells (HPA tissue IHC). Confirm disputed patterns with a negative-control section and a separately validated antibody where available (standard IHC practice).
Could isoforms or epitope changes explain inconsistent staining?
PPP2R5E has 3 annotated isoforms, so determine which sequence region the antibody recognizes before interpreting unequal staining as a biological change (UniProt Q16537). The supplied caption documents paraffin-section staining with A07588-2 but gives no epitope coordinates or isoform coverage (datasheet A07588-2). UniProt lists N-terminal modifications including acetylation at residue 2 and phosphorylation at residues 7, 30, 32 and 34; their effect on this antibody cannot be determined without its epitope information (UniProt Q16537). Compare sections under identical EDTA pH 8.0 retrieval and detection conditions before investigating isoform or modification differences (datasheet A07588-2; standard IHC practice). If interpretation depends on one isoform, seek sequence-specific validation rather than assigning isoform identity from DAB intensity alone (standard IHC practice).
How should I investigate a disputed IHC pattern with IF?
Use IF as an orthogonal localisation check, while keeping chromogenic paraffin IHC as the primary readout; HPA reports mainly cytosolic PPP2R5E in its subcellular observations (HPA subcellular). Multiplex with a validated marker for the cell population being assessed, such as endothelial cells when examining the colonic population reported by HPA, and inspect each channel separately (HPA tissue IHC; standard IF practice). Select fluorophores after checking tissue autofluorescence and include single-label controls to identify spectral bleed-through (standard IF practice). Because PPP2R5E has no annotated transmembrane segment and is mainly cytosolic, use permeabilisation appropriate for access to an intracellular epitope, subject to the antibody’s epitope information (UniProt Q16537 topology; HPA subcellular). Do not transfer the paraffin-section retrieval or fixation assumptions directly to an IF preparation (datasheet A07588-2; standard IF practice).
How can I reduce diffuse or patchy DAB background?
First compare the stained section with a no-primary control and inspect whether diffuse DAB follows tissue folds, edges or damaged areas (standard IHC practice). The documented paraffin example used 10% goat serum blocking and a peroxidase-based secondary system with DAB, providing starting conditions for this catalog antibody (datasheet A07588-2). Include an endogenous-peroxidase blocking step, adequate washes and matched DAB development across sections; these are general chromogenic IHC controls, not PPP2R5E-specific findings (standard IHC practice). If background persists, titrate around the documented 2 μg/ml primary concentration while retaining EDTA retrieval at pH 8.0 (datasheet A07588-2; standard IHC practice). Treat broad staining without cellular boundaries cautiously because HPA describes a general cytoplasmic expression profile (HPA tissue IHC).
How should I score PPP2R5E staining across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Score cytoplasmic DAB within a defined cell population, recording both the percentage of positive cells and intensity to calculate an H-score when graded intensity is reproducible (UniProt Q16537; standard IHC practice). Normalise each result to the number of evaluable cells in that population, or report positive-cell density per mm² of viable tissue when cell counts are impractical (standard IHC practice). Keep EDTA retrieval at pH 8.0, primary concentration at 2 μg/ml and DAB development consistent across the comparison set (datasheet A07588-2; standard IHC practice). Annotate cell identity explicitly: HPA reports Medium staining in colonic endothelial cells and High staining in testicular pachytene spermatocytes (HPA tissue IHC). Exclude necrotic or folded regions and document background thresholds using controls before comparing scores (standard IHC practice).
When should an apparent PPP2R5E-positive result be questioned?
A credible result should show cellular cytoplasmic staining in an identifiable population, consistent with UniProt’s cytoplasmic annotation and HPA’s general cytoplasmic profile (UniProt Q16537; HPA tissue IHC). Question an isolated membrane or predominantly nuclear pattern, because HPA supports a mainly cytosolic location and UniProt annotates no transmembrane segment (HPA subcellular; UniProt Q16537 topology). Check the named cell type rather than treating every brown cell as equivalent: HPA reports Medium colonic endothelial staining and no detected signal in cervical glandular cells (HPA tissue IHC). Edge effects, necrotic areas and endogenous peroxidase can produce misleading DAB signal, so review morphology and a no-primary control before calling these regions positive (standard IHC practice). HPA labels its tissue staining Approved with medium RNA-to-staining consistency, which warrants cautious biological interpretation (HPA tissue IHC).
Boster reagents
Best PPP2R5E / Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform IHC Antibodies
The IHC-validated antibody has human paraffin-section images and listed Human, Mouse, and Rat reactivity (A07588-2 captions; catalog). IF/ICC options have no supplied IF images (catalog).
Real IHC data
Anti-PPP2R5E Antibody ®
Cat # A07588-2
The A07588-2 card will render with its own human colon cancer IHC figure (cards payload). Additional A07588-2 captions document paraffin-section IHC on human colon and stomach cancer tissue; its catalog lists Human, Mouse, and Rat reactivity (A07588-2 captions; catalog).
Which to pick: Choose A07588-2 for human paraffin-section IHC; its own captions document EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody, but do not report the fixative (A07588-2 captions). For IF/ICC, M07588 lists Human, Mouse, and Rat reactivity, while M07588-1 lists Human reactivity and IHC as well; neither has a supplied IF image (catalog). For cross-species work, A07588-2 lists Human, Mouse, and Rat reactivity, although its supplied IHC images show human tissue only; verify the identity of either monoclonal before use because its catalog text describes GluR1 rather than PPP2R5E (catalog; A07588-2 captions; M07588 and M07588-1 dilution_raw).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q16537 (2A5E_HUMAN, Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform).
- Human Protein Atlas. PPP2R5E tissue IHC expression (reliability: Approved).
- Human Protein Atlas. PPP2R5E subcellular location (ICC-IF): Mainly localized to the cytosol. In addition localized to the mid piece and principal piece..
- Human Protein Atlas. PPP2R5E antibody validation summary (2 antibodies).
- Targeting the miR-19b/PPP2R5E axis enhances temozolomide response in glioblastoma via ROS-induced DNA damage. British journal of cancer 2026 — PMC13478537.
- PubMed PMID:8694763 — UniProt-cited evidence.
- PubMed PMID:8703017 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PPP2R5E (Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform). Expected localisation General cytoplasmic tissue staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A07588-2). Validated IHC antibody: A07588-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Testis (Pachytene spermatocytes); negative Cervix. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colon cancer tissue; fixative not specified (datasheet A07588-2); 2. Fixation: Image fixative and duration unreported (datasheet A07588-2); 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 A07588-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A07588-2); 8. Primary antibody: Rabbit anti-PPP2R5E, 2-5 μg/ml (datasheet A07588-2); 9. Primary incubation: Overnight at 4 °C (datasheet A07588-2). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Staining has medium consistency with RNA expression (HPA tissue IHC); Isoform / epitope: 3 isoforms; epitope coverage is unknown (UniProt); Regulation: Expression regulation unreported (UniProt). Evidence: UniProt Q16537, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the cytosol. In addition localized to the mid…, Datasheet A07588-2, PMC13478537. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PPP2R5E/immunohistochemistry-ihc-guide.