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ERAP2 / Endoplasmic reticulum aminopeptidase 2 · IHC design guide
Design Immunohistochemistry for ERAP2
Plan chromogenic ERAP2 IHC in paraffin sections with the human-reactive, IHC-validated antibody (datasheet A04269-1). Use lung macrophages as a high-staining reference and assess cytoplasmic signal by cell type (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
ERAP2 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 tissue staining (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining in several tissues, including immune cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A04269-1) | |
| Positive control | Lung+4 more · see all | |
| Negative control | Cerebellum+4 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 | A secreted variant may alter tissue protein distribution (HPA tissue IHC) | |
| Regulation | Higher expression in spleen and leukocytes (UniProt) | |
| Isoform / epitope | 4 isoforms; antibody epitope coverage is unspecified (UniProt; datasheet A04269-1) |
Section 1
Recommended ERAP2 IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol (datasheet A04269-1) with four published ERAP2 IHC methods (PMC5617457; PMC8725995; PMC7076169; PMC5939618).
| Sample | Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet A04269-1) |
| Fixation | Image fixative and duration unreported (datasheet A04269-1); 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 A04269-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A04269-1) |
| Primary antibody | Rabbit anti-ERAP2, 2-5μg/ml (datasheet A04269-1) |
| Primary incubation | Overnight at 4 °C (datasheet A04269-1) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A04269-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | ERAP2-positive staining in macrophages of lung (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in several tissues, including immune cells. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval for the catalog antibody (datasheet A04269-1); citrate retrieval is documented for AF3830 (PMC5939618).
Section 2
What Is the Expected ERAP2 Staining Pattern?
In paraffin-section IHC, expect cytoplasmic ERAP2 staining, especially in lung macrophages and skin Langerhans cells (HPA: High in both; cytoplasmic tissue profile). ERAP2 has an ER membrane anchor with a lumenal region spanning residues 41–960 (UniProt Q6P179 topology). HPA rates tissue IHC reliability Enhanced, while reporting medium consistency with RNA and a secreted protein variant (HPA: reliability description).
| Strong cytoplasmic stain in lung macrophages or skin Langerhans cells (HPA: High in both). | This matches the strongest listed tissue IHC observations (HPA: tissue IHC). Judge the cells and compartment together; HPA describes a cytoplasmic profile across several tissues, including immune cells (HPA: tissue IHC profile). |
| Predominantly nuclear stain, with little cytoplasmic signal in expected cells (HPA: cytoplasmic tissue profile). | Question specificity or slide processing: nuclear dominance does not match the reported tissue pattern (HPA: tissue IHC profile). Inspect the counterstain, detection controls and antibody conditions before assigning ERAP2 positivity (general IHC practice). |
| Strong stain in cells listed as undetected, such as pancreatic exocrine glandular cells (HPA: Not detected). | Treat this as discordant with that HPA observation, not proof of cross-reactivity (HPA: tissue IHC). Compare tissue context and negative controls; endogenous detection activity can mimic chromogenic signal (general IHC practice). |
| Diffuse stain across cells and tissue spaces, obscuring boundaries (general IHC practice). | High background limits cell-level interpretation (general IHC practice). Review no-primary controls and blocking. Interpret extracellular signal cautiously because HPA reports at least one secreted ERAP2 variant (HPA: reliability description). |
| No stain in lung macrophages or skin Langerhans cells (HPA: High in both). | First check assay performance with the expected positive cells on the same run (HPA: tissue IHC; general IHC practice). An absent signal alone cannot establish ERAP2 absence when the run's positive control also fails (general IHC practice). |
💡Expected ERAP2 appearanceCall a positive result when identifiable lung macrophages or skin Langerhans cells show strong cytoplasmic chromogen (HPA: High; cytoplasmic profile); isolated nuclear stain or broad cell-independent background is suspect (HPA: tissue IHC profile; general IHC practice).
| Cell compartment (UniProt Q6P179 topology). | ERAP2 has one membrane segment at 21–40 and a lumenal region at 41–960 (UniProt Q6P179 topology). Tissue IHC is reported as cytoplasmic; it does not resolve the ER membrane directly (HPA: tissue IHC profile; general IHC practice). |
| Secreted variant and RNA agreement (HPA: reliability description). | HPA reports at least one secreted protein variant and medium staining–RNA consistency (HPA: reliability description). Do not require cellular protein staining to mirror local RNA distribution in every tissue (HPA: reliability description). |
| Antibody-specific IHC evidence (HPA: antibody validation). | CAB025618 is IHC Enhanced; HPA034498 is IHC Supported (HPA: antibody validation). These ratings apply to those antibodies, so record the antibody used when comparing staining patterns (HPA: antibody validation; general IHC practice). |
| Isoforms and glycosylation (UniProt Q6P179). | UniProt lists 4 isoforms and 5 glycosylation sites (UniProt Q6P179). The supplied records do not link either feature to a particular IHC pattern or retrieval response; avoid assigning such effects. |
| IF/ICC Q&A: Should Golgi signal match tissue IHC? (HPA: subcellular ICC-IF; tissue IHC). | HPA calls the Golgi the main approved ICC-IF location, with images from RT-4, U-251MG and U2OS (HPA: subcellular ICC-IF). Tissue IHC reports cytoplasmic staining; compare each assay against its own observation (HPA: tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| The positive tissue control is blank (HPA: High in lung macrophages and skin Langerhans cells). | A failed staining run is possible (general IHC practice). | Check antibody application, retrieval and detection steps against the run record, then repeat with the positive control (general IHC practice). Do not infer target-specific retrieval sensitivity from these records. |
| Nuclei dominate the signal (HPA: cytoplasmic tissue profile). | This compartment disagrees with reported tissue staining (HPA: tissue IHC profile). | Check a no-primary control and the detection setup; interpret only cell-associated cytoplasmic staining that survives those checks (general IHC practice; HPA: tissue IHC profile). |
| Chromogen appears in listed undetected cells (HPA: pancreatic exocrine cells, Not detected). | Cross-reactivity or endogenous detection activity is possible (general IHC practice). | Compare no-primary and detection controls, then reassess cell identity and antibody-specific validation (general IHC practice; HPA: antibody validation). |
| Diffuse chromogen masks cell boundaries (general IHC practice). | Background from blocking or detection conditions is possible (general IHC practice). | Review blocking, washing and detection controls before scoring cells (general IHC practice). Do not automatically discard localized extracellular signal: HPA reports a secreted variant (HPA: reliability description). |
| Stain seems weak compared with local RNA (HPA: medium staining–RNA consistency). | Protein and RNA locations can differ when a variant is secreted (HPA: reliability description). | Score the observed cells against HPA tissue IHC and the run control; avoid treating RNA abundance as an IHC intensity standard (HPA: tissue IHC; reliability description). |
| Two antibodies give different cell patterns (general IHC practice). | Their HPA IHC validation differs: CAB025618 is Enhanced and HPA034498 is Supported (HPA: antibody validation). | Document each antibody and compare its cell pattern with HPA tissue observations and controls before assigning ERAP2 staining (HPA: antibody validation; tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing ERAP2 staining
A04269-1 · IHCIHC analysis of ERAP2 using anti-ERAP2 antibody (A04269-1). ERAP2 was detected in a paraffin-embedded section of human lung cancer tissue. H
A04269-1 · IHCIHC analysis of ERAP2 using anti-ERAP2 antibody (A04269-1). ERAP2 was detected in a paraffin-embedded section of human lymphoma tissue. Heat
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000164308-ERAP2/tissue/cerebral+cortex#imid_6598584
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000164308-ERAP2/tissue/colon#imid_6596006
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000164308-ERAP2/tissue/liver#imid_6595991
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000164308-ERAP2/tissue/kidney#imid_6596000
HPA · ICC-IF RT-4Human Protein Atlas immunofluorescence, RT-4, antibody HPA064360; green = ERAP2, blue = nucleus, red = microtubules.
HPA · ICC-IF RT-4Human Protein Atlas immunofluorescence, RT-4, antibody HPA064360; green = ERAP2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for ERAP2 IHC & IF
🧪Run lung first and expect macrophages to stain (HPA: High in lung macrophages). Use cerebellum as the negative tissue, focusing on granular-layer cells (HPA: Not detected in cerebellar granular-layer cells); on the lung slide, use neighboring cells without signal as internal negative comparators rather than assuming a particular cell type is negative.
Positive control tissue: Lung (Macrophages, HPA High)
Negative control tissue: Cerebellum (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show ERAP2 in RT-4, U-251MG, U2OS, with annotated localisation: Golgi apparatus (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control; a concentration-matched rabbit isotype control for the rabbit catalog antibody (selected-SKU caption: rabbit anti-ERAP2); and a matched ERAP2-knockout biological negative. For lung sections developed with the caption’s biotin-based DAB method, check endogenous peroxidase and biotin background (selected-SKU caption: SABC and DAB; standard IHC practice).
⚠️Feasibility: A target-specific fixation window and fixation effect are unreported; the exact selected-SKU tissue-IHC caption also leaves the fixative unstated (selected-SKU caption: fixative not stated). The caption uses heat retrieval in EDTA at pH 8.0, but does not establish that retrieval is required or that frozen sections or IF would be easier (selected-SKU caption: heat-mediated EDTA retrieval in a paraffin section). Lung macrophage staining warrants careful background assessment during scoring (HPA: High in lung macrophages; standard IHC practice).
HPA tissue IHC evidence for ERAP2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. At least one protein variant secreted, tissue location of RNA and protein might differ and correlation is complex.). 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 |
|---|---|---|---|---|
| Lung | Macrophages | High | Protein (IHC) | HPA → |
| Skin | Langerhans | High | Protein (IHC) | HPA → |
| Adipose tissue | Adipocytes | Medium | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
| Pancreas | Exocrine glandular cells | Not detected | Protein (IHC) | HPA → |
| Parathyroid gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Salivary gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Smooth muscle | Smooth muscle cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced ERAP2 IHC Tips
Use the catalog antibody’s tissue IHC conditions as a starting point, then assess staining by cell type and compartment (datasheet A04269-1; HPA tissue IHC).
Which retrieval condition should I use for ERAP2 in paraffin sections?
Start with heat-mediated retrieval in EDTA pH 8.0 for paraffin sections (datasheet A04269-1). The selected lung cancer tissue example used this condition before incubation with 2 μg/ml catalog antibody overnight at 4°C (datasheet A04269-1). If staining is weak, vary heating duration or trial another retrieval buffer on adjacent sections while keeping antibody concentration and detection constant (standard IHC practice). Compare signal in macrophages with background in nearby cells, because lung macrophages show high ERAP2 staining in the tissue profile (HPA: High in lung macrophages). Record retrieval conditions for every section so differences in intensity remain interpretable (standard IHC practice).
Could fixation explain weak ERAP2 staining in my tissue sections?
ERAP2-specific fixation sensitivity is unknown from the supplied evidence; the selected paraffin-section caption does not state a fixative (datasheet A04269-1). Document the fixative, fixation time, section thickness and storage conditions before changing the antibody protocol (standard IHC practice). Run sections from the same block through the established EDTA pH 8.0 retrieval and 2 μg/ml antibody incubation to limit processing differences (datasheet A04269-1). If fixation conditions differ across samples, compare them with matched controls processed in parallel and avoid treating intensity differences alone as biological differences (standard IHC practice). Do not infer fixation tolerance from tissue staining patterns or protein topology (HPA tissue IHC; UniProt Q6P179 topology).
Should ERAP2 staining appear cytoplasmic, perinuclear or at the cell surface?
Score predominantly intracellular staining in the context of the tissue compartment: the tissue profile reports cytoplasmic expression, while the subcellular profile places ERAP2 mainly in the Golgi apparatus (HPA tissue IHC; HPA subcellular). UniProt annotates an endoplasmic reticulum membrane protein with a cytoplasmic 1–20 segment, transmembrane 21–40 segment and lumenal 41–960 segment (UniProt Q6P179 topology). A concentrated perinuclear pattern can therefore merit comparison with the reported organelle locations, although chromogenic IHC alone cannot resolve those organelles (HPA subcellular; standard IHC practice). Assess staining within identified cells, because high signal in lung macrophages could be mistaken for staining in adjacent tissue cells (HPA: High in lung macrophages). Treat isolated surface-only staining as a reason to recheck specificity and tissue morphology (UniProt Q6P179 topology; standard IHC practice).
How can I judge whether this antibody detects all ERAP2 isoforms?
Do not assume pan-isoform recognition: ERAP2 has 4 annotated isoforms, but the supplied antibody caption does not map its epitope (UniProt Q6P179 isoforms; datasheet A04269-1). Obtain the immunogen or epitope sequence and compare it with the sequence retained in each isoform before assigning staining to a particular variant (standard IHC practice). The annotated membrane topology places residues 1–20 in the cytoplasm and 41–960 in the lumen, which matters when assessing epitope accessibility (UniProt Q6P179 topology). Five annotated glycosylation sites occur at residues 85, 119, 219, 405 and 650, but their effect on this antibody’s staining is untested here (UniProt Q6P179 glycosylation; datasheet A04269-1). Report staining as antibody-detected ERAP2 unless isoform coverage has been established (standard IHC practice).
How should I use IF to investigate ambiguous ERAP2 IHC staining?
Use IF as a complementary localisation check rather than applying the paraffin IHC conditions unchanged; the selected caption documents chromogenic tissue IHC (datasheet A04269-1). Multiplex ERAP2 with a cell-type marker such as CD68 when assessing lung macrophages, which show high staining in the tissue profile (HPA: High in lung macrophages; standard IF practice). Select spectrally separated fluorophores and examine an unstained section so tissue autofluorescence does not masquerade as ERAP2 signal (standard IF practice). If the antibody epitope is lumenal, permeabilise intracellular membranes; a cytoplasmic-side epitope may require different access conditions, and its position is not supplied here (UniProt Q6P179 topology; datasheet A04269-1). Compare the resulting pattern with reported Golgi localisation while preserving cell morphology and exposure settings (HPA subcellular; standard IF practice).
What should I change when ERAP2 DAB staining is diffuse or widespread?
First compare a no-primary control with the stained section to separate detection-system background from antibody-dependent signal (standard IHC practice). The selected protocol used 10% goat serum blocking, a biotinylated secondary, a streptavidin–biotin complex and DAB; retain those details when troubleshooting (datasheet A04269-1). Apply a peroxidase block and assess endogenous biotin background where relevant, because enzyme and biotin-based detection can produce signal unrelated to ERAP2 (standard IHC practice). If background persists, titrate the catalog antibody around the reported 2 μg/ml concentration and inspect wash quality without changing several conditions together (datasheet A04269-1; standard IHC practice). Interpret diffuse staining against cell morphology and the reported cytoplasmic tissue pattern (HPA tissue IHC; standard IHC practice).
How should I quantify ERAP2 staining across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and viable analysis area before scoring, then use the same rules across slides (standard IHC practice). An H-score combines intensity with the percentage of positive cells; alternatively, report percentage positive or positive-cell density per mm² when cell counts are reliable (standard IHC practice). Normalise density to viable tissue area and compare intensity within the same cell type, because ERAP2 staining differs among annotated tissue cell populations (HPA tissue IHC; standard IHC practice). In lung sections, score macrophages separately from other cells rather than allowing their high staining to dominate a whole-section value (HPA: High in lung macrophages). Keep retrieval, DAB development and imaging settings consistent for samples being compared (standard IHC practice).
How do I distinguish true ERAP2 staining from tissue artefact?
A credible result should follow cell identity and an intracellular pattern: lung macrophages show high tissue staining, and the tissue profile describes cytoplasmic expression (HPA tissue IHC). Check whether apparent positive cells are macrophages rather than adjacent cells, and compare the pattern with the reported Golgi localisation and endoplasmic reticulum membrane topology (HPA subcellular; UniProt Q6P179 topology; standard IHC practice). Discount staining confined to section edges, folds or necrotic regions after checking matched intact tissue (standard IHC practice). Use a no-primary control and peroxidase blocking assessment to identify DAB signal caused by the detection workflow (standard IHC practice). Interpret disagreements cautiously: the tissue profile has Enhanced reliability but only medium RNA–protein consistency and notes that protein-variant location can complicate correlation (HPA tissue IHC).
Boster reagents
Best ERAP2 / Endoplasmic reticulum aminopeptidase 2 IHC Antibodies
A04269-1 has real IHC data from human paraffin-embedded lung cancer and lymphoma sections (A04269-1 IHC captions). No IF data are provided (catalog: A04269-1 image records).
Real IHC data
Anti-ERAP2 Antibody ®
Cat # A04269-1
A04269-1 is listed for human IHC and has images from paraffin-embedded human lung cancer and lymphoma sections (catalog: A04269-1 applications/reactivity; A04269-1 IHC captions). No IF image or IF/ICC application is listed for A04269-1 (catalog: A04269-1 image records/applications).
Which to pick: For tissue IHC, choose A04269-1: its own captions document paraffin sections with EDTA pH 8.0 retrieval and 2 μg/ml primary antibody (A04269-1 IHC captions). No SKU in the payload supports an IF/ICC or cross-species recommendation; A04269-1 has no listed IF/ICC application, is human-reactive, and has no reported clone (catalog: A04269-1 applications/reactivity/clone). The fixative is unreported (A04269-1 IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q6P179 (ERAP2_HUMAN, Endoplasmic reticulum aminopeptidase 2).
- Human Protein Atlas. ERAP2 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. ERAP2 subcellular location (ICC-IF): Mainly localized to the Golgi apparatus..
- Human Protein Atlas. ERAP2 antibody validation summary (3 antibodies).
- Endoplasmic reticulum aminopeptidase 2 involvement in metastasis of oral cavity squamous cell carcinoma discovered by proteome profiling of primary cancer cells. Oncotarget 2017 — PMC5617457.
- ERAP2 Is Associated With Immune Infiltration and Predicts Favorable Prognosis in SqCLC. Frontiers in immunology 2021 — PMC8725995.
- The Differential Expression of ERAP1/ERAP2 and Immune Cell Activation in Pre-eclampsia. Frontiers in immunology 2020 — PMC7076169.
- The role of endoplasmic reticulum aminopeptidase 2 in modulating immune detection of choriocarcinoma. Biology of reproduction 2018 — PMC5939618.
- PubMed PMID:12799365 — UniProt-cited evidence.
- PubMed PMID:15691326 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for ERAP2 (Endoplasmic reticulum aminopeptidase 2). Expected localisation Cytoplasmic tissue staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A04269-1). Validated IHC antibody: A04269-1 at 2-5μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Lung (Macrophages); negative Cerebellum. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet A04269-1); 2. Fixation: Image fixative and duration unreported (datasheet A04269-1); 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 A04269-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A04269-1); 8. Primary antibody: Rabbit anti-ERAP2, 2-5μg/ml (datasheet A04269-1); 9. Primary incubation: Overnight at 4 °C (datasheet A04269-1). Watch for: Fixation: Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific); Caveat: A secreted variant may alter tissue protein distribution (HPA tissue IHC); Isoform / epitope: 4 isoforms; antibody epitope coverage is unspecified (UniProt; datasheet A04269-1); Regulation: Higher expression in spleen and leukocytes (UniProt). Evidence: UniProt Q6P179, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the Golgi apparatus., Datasheet A04269-1, PMC5617457, PMC8725995. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/ERAP2/immunohistochemistry-ihc-guide.