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TREX2 / Three prime repair exonuclease 2 · IHC design guide
Design Immunohistochemistry for TREX2
Plan TREX2 IHC-P around nuclear staining in several tissues (HPA tissue IHC). Compare a medium-staining tissue such as tonsil with a documented not-detected tissue such as adipose tissue, and interpret results cautiously because tissue IHC reliability is uncertain (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
TREX2 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 several tissues (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in glandular and germinal center cells (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen) | |
| Positive control | Adrenal gland+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 consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Tissue IHC staining has uncertain reliability (HPA tissue IHC) | |
| Regulation | Staining-related regulation is unreported (UniProt) | |
| Isoform / epitope | 2 isoforms; epitope impact is undetermined (UniProt) |
Section 1
Recommended TREX2 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is paired with published TREX2 protocols for laryngeal cancer sections (PMC6499986) and HNSCC tissue microarrays (PMC4673170).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet A08960); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat-induced epitope retrieval in Tris-EDTA buffer, pH 9.0, 20 min at 95–98 °C (standard rule: nuclear antigen) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% normal serum of the secondary host, 30 min, room temperature (standard) |
| Primary antibody | Rabbit anti-TREX2, 2.5 μg/mL (datasheet A08960) |
| Primary incubation | Overnight at 4 °C (standard) |
| Detection | HRP-polymer secondary, DAB chromogen 5–10 min (standard) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | TREX2-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: Nuclear expression in several tissues. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0 retrieval at 95–98 °C for 20 min (page retrieval: nuclear antigen); the HNSCC protocol used low-pH retrieval (PMC4673170).
Section 2
What Is the Expected TREX2 Staining Pattern?
TREX2 is a nuclear protein with no transmembrane segment (UniProt Q9BQ50: location and topology). In paraffin section IHC, expect nuclear staining in cell populations reported at medium intensity, including skin fibroblasts, testis Leydig cells, and lymph node germinal center cells (HPA: tissue IHC). Treat the pattern as a guide for comparison: the available tissue IHC antibody is rated Uncertain (HPA: antibody IHC validation).
| Distinct nuclear chromogen in skin fibroblasts, testis Leydig cells, or lymph node germinal center cells. | This fits TREX2's nuclear location and the reported medium staining in those cell populations (UniProt Q9BQ50: location; HPA: tissue IHC). Judge the named cells separately from surrounding tissue. A matching pattern is supportive, but the antibody's IHC rating is Uncertain, so morphology alone does not establish specificity (HPA: antibody IHC validation). |
| Predominantly cytoplasmic, membranous, or extracellular staining with little nuclear signal. | This conflicts with the annotated nuclear location and absence of a transmembrane segment (UniProt Q9BQ50: location and topology). Check the counterstain to locate nuclei, then review background and detection controls as general IHC practice. Do not score a compartment that disagrees with the expected pattern as convincing TREX2 without independent validation. |
| Strong staining in adipocytes or liver cholangiocytes, especially when expected nuclei are weak. | Those cell populations are reported as not detected in HPA tissue IHC (HPA: adipose tissue and liver). Unexpected staining warrants a cross-reactivity or endogenous detection activity check under general IHC practice. HPA's Uncertain IHC rating limits how confidently any single positive or negative field can be interpreted (HPA: antibody IHC validation). |
| Diffuse chromogen across nuclei and surrounding tissue, with poorly defined cell boundaries. | This is hard to reconcile with a cell-specific nuclear pattern (UniProt Q9BQ50: location; HPA: nuclear expression in several tissues). General IHC causes to assess include inadequate blocking, excess detection reagent, or incomplete washing. Compare a no-primary control and nearby cell populations before assigning any diffuse color to TREX2. |
| No visible signal in a section containing skin fibroblasts or testis Leydig cells. | These are reported at medium intensity, making them useful comparison populations, though they are not guaranteed positives in every preparation (HPA: tissue IHC; HPA: IHC reliability Uncertain). First verify that the relevant cells are present and the detection run worked. Review the antibody's validated IHC-P conditions before calling the tissue negative. |
💡Expected TREX2 appearanceA plausible positive is medium nuclear staining in the named HPA cell populations; prominent staining outside nuclei or in HPA not-detected populations is suspect (HPA: tissue IHC; UniProt Q9BQ50: location).
| Compartment and topology | TREX2 is annotated in the nucleus, with no transmembrane segment or signal peptide (UniProt Q9BQ50: location, topology and processing). Nuclear localization is therefore the primary reading criterion; these annotations do not explain an isolated membrane or extracellular pattern. |
| Cell population and tissue | HPA reports medium staining in several named cell populations, while adipocytes and liver cholangiocytes are not detected (HPA: tissue IHC). Compare the specified cells, not whole-section darkness. A not-detected entry describes that observation; it is not proof that every cell or preparation from the tissue must be negative. |
| IHC evidence strength | HPA describes nuclear expression in several tissues, but rates tissue IHC reliability and the listed antibody's IHC validation as Uncertain (HPA: tissue IHC; HPA: antibody IHC validation). Use the distribution as an expectation that needs controls, rather than a definitive specificity test. |
| Isoforms and processing | UniProt lists 2 isoforms and a chain spanning residues 1–236, with no signal peptide or propeptide (UniProt Q9BQ50: isoforms and processing). The payload gives no antibody epitope or isoform coverage, so it cannot predict an isoform-specific stain or justify a processing-based explanation for missing signal. |
| RNA versus protein readout | HPA calls RNA tissue enhanced in blood vessel and skin, while its protein IHC observations specify particular stained cell populations (HPA: RNA specificity and tissue IHC). Use the protein observations for slide interpretation; RNA enrichment alone does not establish strong chromogenic staining in every cell of either tissue. |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected nuclei are blank in a reported medium-staining population. | The relevant cells may be absent from the field, or the IHC run may have failed; HPA medium staining is observational rather than guaranteed (HPA: tissue IHC; HPA: reliability Uncertain). | Confirm cell identity on the counterstain, check a working run control, and review the catalog antibody's IHC-P protocol as general IHC practice. The supplied sources do not establish TREX2-specific fixation or retrieval sensitivity. |
| Color is strongest outside nuclei. | The distribution conflicts with TREX2's nuclear annotation (UniProt Q9BQ50: location); nonspecific staining or detection background are general IHC possibilities. | Compare nuclear counterstain alignment and a no-primary control. Score only convincing cell-associated nuclear signal while investigating the discordant compartment under general IHC practice. |
| Unexpected cells stain as strongly as the comparison population. | Cross-reactivity or endogenous detection activity may contribute under general IHC practice; HPA reports some populations as not detected and rates IHC Uncertain (HPA: tissue IHC and validation). | Check tissue morphology and detection controls, including the relevant endogenous activity control for the chromogen system. Reassess the claim against the specific HPA cell population, not the tissue name alone. |
| The whole section shows diffuse color. | General IHC background can obscure the nuclear, cell-specific distribution expected from UniProt and HPA (UniProt Q9BQ50: location; HPA: tissue IHC). | Inspect a no-primary control and review blocking, reagent concentration, washing, and chromogen development as general IHC practice; repeat scoring only where nuclei and cell boundaries remain clear. |
| A reported not-detected population has no staining. | That finding agrees with the listed HPA observation for the specific cell population, such as adipocytes or liver cholangiocytes (HPA: tissue IHC). | Record the cell population and run control. Do not treat a blank field alone as proof of antibody specificity or successful staining; HPA rates the IHC evidence Uncertain (HPA: antibody IHC validation). |
| IF/ICC: should a fluorescent nuclear pattern be expected? | UniProt annotates TREX2 as nuclear, but HPA supplies no main ICC-IF location or cell-line images for it (UniProt Q9BQ50: location; HPA: subcellular record). | Treat nuclear fluorescence as a hypothesis, not an HPA-validated ICC-IF result. Assess IF/ICC staining with its own controls and guide; the tissue IHC observations do not establish an IF/ICC pattern. |
Experiment evidence
IHC & IF images showing TREX2 staining
A08960 · IHCImmunohistochemistry of TREX2 in human liver tissue with TREX2 antibody at 2.5 μg/mL.
A08960 · IFImmunofluorescence of TREX2 in Human Liver cells with TREX2 antibody at 20 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000183479-TREX2/tissue/cerebral+cortex#imid_15313866
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000183479-TREX2/tissue/colon#imid_15312776
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000183479-TREX2/tissue/liver#imid_15312785
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000183479-TREX2/tissue/kidney#imid_15312786
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for TREX2 IHC & IF
🧪Run adrenal gland first: glandular cells should show nuclear TREX2 staining (HPA: Medium in adrenal gland glandular cells; UniProt Q9BQ50: nucleus). Use adipose tissue as the negative tissue (HPA: Not detected in adipocytes); non-glandular cells on the adrenal slide should show little or no nuclear signal, but verify their status rather than assuming they are TREX2-negative (HPA: glandular-cell result only).
Positive control tissue: Adrenal gland (Glandular cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for TREX2; derive a cell-line control from the positive tissue's cell type (Glandular cells) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host species, immunoglobulin class and concentration; use TREX2 knockout tissue as a biological specificity control if available (standard IHC practice). Block endogenous peroxidase for chromogenic detection and endogenous biotin if using avidin–biotin detection, particularly when interpreting background in adrenal sections (standard IHC practice).
⚠️Feasibility: No target-specific fixation window or antigen-retrieval dependency is reported in the supplied evidence; optimize retrieval empirically for paraffin sections (standard IHC practice). The A08960 human liver IHC caption reports 2.5 μg/mL, but its fixative is unreported (selected IHC caption). The evidence does not establish whether frozen sections or IF/ICC would be easier (HPA subcellular: no ICC-IF images); assess erythrocyte-associated peroxidase background in blood-containing adrenal areas (standard IHC practice).
HPA tissue IHC evidence for TREX2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — External characterization data supports antibody staining.). 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Endometrium | Glandular cells | Medium | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Medium | Protein (IHC) | HPA → |
| Lymph node | Germinal center cells | Medium | Protein (IHC) | HPA → |
| Skin | Fibroblasts | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
| Epididymis | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Fallopian tube | Glandular cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced TREX2 IHC Tips
Troubleshoot TREX2 staining in paraffin sections by checking nuclear localisation, cell identity, assay controls, and the limits of the available tissue evidence.
How should I adjust retrieval when nuclear TREX2 staining is weak?
Start with Tris-EDTA pH 9.0 HIER at 95–98 °C for 20 min (page retrieval setting: nuclear antigen). Allow sections to cool in retrieval buffer, then compare a short antibody titration on serial sections while holding detection and development constant (standard IHC practice). If nuclear signal remains weak, trial a shorter or longer heating interval; evaluate tissue integrity and background alongside signal because retrieval can change both (standard IHC practice). The liver image used 2.5 µg/mL antibody, but its caption reports no retrieval conditions, so it cannot establish an optimal retrieval setting (A08960 tissue-IHC caption).
Could fixation explain weak or diffuse TREX2 staining?
TREX2-specific sensitivity to fixation is unknown because no target-specific fixation evidence is supplied for this IHC assay (supplied fixation evidence: none). The selected liver caption does not state its fixative, so do not treat that image as a formalin-fixed reference (A08960 tissue-IHC caption). For troubleshooting, compare sections with documented fixation histories using the same pH 9.0, 20 min retrieval setting and identical detection conditions (page retrieval setting; standard IHC practice). Record fixation duration where known, assess morphology, and use a matched positive-control section; a change in staining across specimens alone cannot identify fixation as the cause (standard IHC practice).
Where should convincing TREX2 staining appear in a tissue section?
Score nuclear staining first: TREX2 is assigned to the nucleus, and the tissue IHC profile describes nuclear expression across several tissues (UniProt Q9BQ50 subcellular; HPA tissue IHC). The protein has no annotated transmembrane segment or signal peptide, so strong continuous membrane or extracellular staining needs independent validation (UniProt Q9BQ50 topology and processing). Check whether the chromogen overlaps hematoxylin-defined nuclei in intact cells rather than pooling over lumina or damaged tissue (standard IHC practice). Nuclear staining in a cell population reported as positive can support interpretation, but the HPA tissue-antibody reliability is Uncertain (HPA tissue IHC).
How do isoforms affect interpretation of TREX2 staining?
Two TREX2 isoforms are listed, but the supplied evidence does not map the catalog antibody epitope to either one (UniProt Q9BQ50 isoforms; supplied antibody evidence). Consequently, a positive section cannot identify which isoform contributes to the chromogenic signal without isoform-specific validation (UniProt Q9BQ50 isoforms; standard IHC interpretation). TREX2 has no annotated glycosylation sites, modified residues, or propeptide, and its annotated chain spans residues 1–236 (UniProt Q9BQ50 processing and PTMs). If staining differs across samples, compare antigen retrieval and controls before attributing it to isoform expression, since the epitope's fixation accessibility is also unreported (supplied antibody evidence; standard IHC practice).
How can I check the nuclear IHC pattern by multiplex IF?
Use IF as an independent localisation check, since the supplied catalog evidence describes tissue IHC rather than an IF validation for this antibody (A08960 tissue-IHC caption; supplied antibody evidence). Pair TREX2 with a validated marker for the expected cell population, such as fibroblasts in skin, and include a nuclear counterstain to inspect overlap (HPA tissue IHC: skin fibroblasts; standard IF practice). Choose a fluorophore channel after measuring tissue autofluorescence, with an unstained section and single-stain controls for multiplex interpretation (standard IF practice). Because TREX2 is nuclear and has no transmembrane segment, trial mild permeabilisation to permit nuclear access; optimise it separately from the paraffin IHC workflow (UniProt Q9BQ50 subcellular and topology; standard IF practice).
What should I check when TREX2 chromogen appears across the section?
Compare no-primary and matched control sections to distinguish antibody-dependent staining from detection-system deposits (standard IHC practice). In a peroxidase-based chromogenic workflow, test a 3% hydrogen peroxide block for 10 min as a general starting condition, then optimise against tissue damage (standard IHC practice). Reduce excessive primary concentration or chromogen development and improve washing if diffuse signal obscures nuclei; the selected liver caption reports 2.5 µg/mL only for its own image (standard IHC practice; A08960 tissue-IHC caption). Inspect tissue edges, folds, necrotic regions, and pigment before assigning broad brown staining to TREX2, whose expected location is nuclear (standard IHC practice; UniProt Q9BQ50 subcellular).
How should I score TREX2 across heterogeneous tissue regions? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and intact analysis regions before scoring, then record the percentage of TREX2-positive nuclei and staining intensity using fixed thresholds (standard IHC practice; UniProt Q9BQ50 subcellular). An H-score can combine percentage at each intensity as Σ(percent × intensity), with intensity graded 0–3 and a resulting range of 0–300 (standard IHC practice). Normalise positive-cell counts to all evaluable nuclei in the same cell population, or report positive-cell density per mm² of viable analysed tissue (standard IHC practice). Keep retrieval, imaging, and chromogen development consistent across groups, and exclude folds and necrosis under prespecified rules (standard IHC practice).
How do I distinguish true TREX2 staining from artefact?
Prioritise reproducible staining in intact nuclei within a defined cell population, consistent with TREX2's nuclear annotation and the reported tissue profile (UniProt Q9BQ50 subcellular; HPA tissue IHC). Medium staining is reported in skin fibroblasts and testis Leydig cells, whereas liver cholangiocytes were not detected in the HPA assay (HPA tissue IHC). Treat strong membrane staining, section-edge gradients, necrotic deposits, and signal persisting without primary antibody as reasons to investigate localisation or assay background (UniProt Q9BQ50 topology; standard IHC practice). The selected liver antibody image establishes staining at 2.5 µg/mL, while HPA rates its separate tissue-antibody evidence Uncertain; neither observation alone proves cellular specificity (A08960 tissue-IHC caption; HPA tissue IHC).
Boster reagents
Best TREX2 / Three prime repair exonuclease 2 IHC Antibodies
A08960 has IHC data from human liver tissue and IF data from human liver cells; its listed reactivity is human, mouse, and rat (catalog image captions; catalog reactivity).
Real IHC data
Anti-TREX2 Antibody
Cat # A08960
A08960 will render with an IHC image of human liver tissue at 2.5 μg/mL (IHC image caption). The same SKU lists IF and shows human liver cells at 20 μg/mL (catalog applications; IF image caption).
Which to pick: Choose A08960 for paraffin-section tissue IHC based on its IHC-P listing and human liver tissue image; the fixative is unreported (catalog applications; IHC image caption). Choose A08960 for IF based on its human liver cell image; ICC-specific validation is unreported (catalog applications; IF image caption). It is the listed option for human, mouse, and rat reactivity, although both images show human samples and clonality is unreported (catalog reactivity; IHC/IF image captions; catalog clone field).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9BQ50 (TREX2_HUMAN, Three prime repair exonuclease 2).
- Human Protein Atlas. TREX2 tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. TREX2 subcellular location (ICC-IF): Highest expression in HEK293: 3.7 nTPM.
- Human Protein Atlas. TREX2 antibody validation summary (1 antibodies).
- DNA methylation at an enhancer of the three prime repair exonuclease 2 gene (TREX2) is linked to gene expression and survival in laryngeal cancer. Clinical epigenetics 2019 — PMC6499986.
- Multifaceted role of TREX2 in the skin defense against UV-induced skin carcinogenesis. Oncotarget 2015 — PMC4673170.
- PubMed PMID:10391904 — UniProt-cited evidence.
- PubMed PMID:11278605 — UniProt-cited evidence.
- PubMed PMID:11279105 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for TREX2 (Three prime repair exonuclease 2). Expected localisation Nuclear staining in several tissues (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: A08960 at 2.5 μg/mL (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Tissue sections; selected-image fixative not specified (standard IHC workflow); 2. Fixation: Image fixative and duration unreported (datasheet A08960); 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-induced epitope retrieval in Tris-EDTA buffer, pH 9.0 , 20 min at 95–98 °C…; 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% normal serum of the secondary host, 30 min , room temperature (standard); 8. Primary antibody: Rabbit anti-TREX2, 2.5 μg/mL (datasheet A08960); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Tissue IHC staining has uncertain reliability (HPA tissue IHC); Isoform / epitope: 2 isoforms; epitope impact is undetermined (UniProt); Regulation: Staining-related regulation is unreported (UniProt). Evidence: UniProt Q9BQ50, HPA tissue IHC · Uncertain, HPA cell-line RNA · Highest expression in HEK293: 3.7 nTPM, Datasheet A08960, PMC6499986, PMC4673170. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/TREX2/immunohistochemistry-ihc-guide.