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UBA2 / SUMO-activating enzyme subunit 2 · IHC design guide
Design Immunohistochemistry for UBA2
This guide helps plan chromogenic IHC-P for UBA2 using nuclear staining in most cell types as a reference (HPA tissue IHC). It highlights the lack of detected staining in placental trophoblasts when interpreting results (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
UBA2 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 in most tissue cell types (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in most cells; trophoblasts undetected (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6 HIER, heat-mediated (datasheet A03816-2) | |
| Positive control | Adipose tissue+4 more · see all | |
| Negative control | Placenta |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Placental trophoblasts may lack signal (HPA tissue IHC) | |
| Regulation | Low tissue specificity; stimulus effects unreported (HPA RNA specificity) | |
| Isoform / epitope | 2 isoforms; epitope coverage is unknown (UniProt) |
Section 1
Recommended UBA2 IHC & IF Protocols
The catalog antibody protocol uses citrate pH 6 heat retrieval (datasheet A03816-2). The published IHC protocols below cover colorectal cancer, gastric cancer, and synovial tissue (PMC6236309; PMC6235804; PMC7526534).
| Sample | Paraffin-embedded human colon cancer tissue; fixative not specified (datasheet A03816-2) |
| Fixation | Image fixative and duration unreported (datasheet A03816-2); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Citrate pH 6, 20 min (datasheet A03816-2) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A03816-2) |
| Primary antibody | Rabbit anti-UBA2, 0.5-1μg/ml (datasheet A03816-2) |
| Primary incubation | Overnight at 4 °C (datasheet A03816-2) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A03816-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | UBA2-positive staining in adipocytes of adipose tissue (HPA tissue IHC: High). HPA tissue profile: Nuclear expression in essentially all cell types, except for placental trophoblasts. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6 heat retrieval (datasheet A03816-2); the colorectal protocol also uses heated citrate, though it does not state the pH (PMC6236309).
Section 2
What Is the Expected UBA2 Staining Pattern?
UBA2 is observed mainly in nuclei across essentially all cell types, with placental trophoblasts as the reported exception (HPA: tissue IHC, Supported; medium consistency with RNA). Nucleoplasmic localisation is also supported by ICC-IF (HPA: subcellular). UBA2 can shuttle between nucleus and cytoplasm and has no transmembrane segment (UniProt Q9UBT2: localisation, topology).
| Distinct nuclear staining in adipocytes, adrenal glandular cells or bone marrow hematopoietic cells. | This fits the expected compartment and the reported High staining in those cells (HPA: tissue IHC). Compare nuclei with adjacent unstained areas and the counterstain when scoring. |
| Predominantly cytoplasmic staining with little nuclear signal. | Review localisation before scoring it as positive: HPA observes mainly nuclear staining, although UBA2 can shuttle through cytoplasm (HPA: tissue IHC; UniProt Q9UBT2: localisation). Check whether the colour follows cell boundaries or a section artefact. |
| Convincing staining in placental trophoblasts. | Treat this as unexpected because trophoblastic cells were not detected in the HPA tissue IHC profile (HPA: placenta). Check cell identification, antibody cross-reactivity and endogenous chromogen activity; do not treat the whole placenta as a negative control. |
| Diffuse colour over cells and empty slide areas, obscuring nuclei. | This does not resolve the expected nuclear pattern (HPA: tissue IHC). Background from the detection workflow is a general IHC possibility; assess a detection-only control before assigning UBA2 positivity. |
| No nuclear signal in an otherwise interpretable adrenal gland or bone marrow section. | That conflicts with High staining reported for adrenal glandular or bone marrow hematopoietic cells (HPA: tissue IHC). First verify that those cells are present; then review the general IHC controls and staining workflow. |
💡Expected UBA2 appearanceCall a result positive when interpretable nuclei stain in the relevant cells, especially HPA High examples; dominant diffuse haze or trophoblast staining warrants investigation (HPA: tissue IHC).
| Tissue and cell selection | Adipocytes, adrenal glandular cells and bone marrow hematopoietic cells have reported High staining; placental trophoblasts were not detected (HPA: tissue IHC). Select controls by cell type. |
| Compartment used for scoring | Score resolved nuclear staining against the HPA tissue pattern (HPA: tissue IHC). Cytoplasmic signal needs context because UBA2 shuttles between compartments (UniProt Q9UBT2: localisation). |
| Antibody evidence | HPA041436 is listed as Supported for IHC and ICC, while tissue IHC has medium consistency with RNA (HPA: antibody validation; tissue reliability). These ratings support interpretation without guaranteeing a particular section's result. |
| Protein form and epitope | UBA2 has a continuous annotated chain, no signal peptide and no transmembrane segment; two isoforms are listed (UniProt Q9UBT2: processing, topology, isoforms). Epitope coverage is not supplied, so isoform recognition cannot be assigned. |
| IF/ICC question: where should UBA2 appear? | Mainly in the nucleoplasm (HPA: ICC-IF, supported). UniProt also lists cytoplasm and nuclear shuttling (UniProt Q9UBT2: localisation); the IF/ICC guide covers its own workflow. |
| Situation | Likely cause | Next action |
|---|---|---|
| No stain in expected positive cells. | A missing signal conflicts with reported High staining in adrenal glandular cells or bone marrow hematopoietic cells (HPA: tissue IHC); a workflow failure is possible. | Confirm the expected cell population is present, then check a positive control, reagent activity, antigen retrieval and detection steps (general IHC practice). |
| Placental trophoblasts appear positive. | Their reported level is Not detected (HPA: placenta); cell misidentification, cross-reactivity or endogenous detection activity may explain the colour (general IHC practice). | Recheck cell identity and compare with a detection-only control; repeat with the IHC-validated antibody if the result remains unclear (general IHC practice; HPA: antibody validation). |
| Cytoplasmic stain dominates the section. | UBA2 can shuttle through cytoplasm (UniProt Q9UBT2: localisation), but the observed tissue and ICC-IF patterns are chiefly nuclear (HPA: tissue IHC; subcellular). | Inspect nuclear counterstain and cell outlines; compare an HPA High cell population on the same run before scoring the cytoplasmic colour. |
| Diffuse haze masks nuclei. | Nonspecific background may obscure the expected nuclear pattern (HPA: tissue IHC; general IHC practice). | Review blocking, washes and chromogen development; compare a detection-only control and score only resolved cellular staining (general IHC practice). |
| Signal is strongest at section edges or in deposits. | Uneven reagent coverage or chromogen deposits can create apparent staining (general IHC practice); neither describes the HPA nuclear cell pattern (HPA: tissue IHC). | Assess central intact tissue, inspect the counterstain and repeat the staining run if deposits prevent nuclear scoring (general IHC practice). |
| Weak nuclear colour varies across a section. | The HPA profile reports cell-specific intensity, including High examples, but does not establish UBA2-specific fixation sensitivity (HPA: tissue IHC). | Compare the same identified cell type across intact areas and a positive control; review section quality and processing as general IHC checks. |
Experiment evidence
IHC & IF images showing UBA2 staining
A03816-2 · IHCIHC analysis of SAE2/UBA2 using anti-SAE2/UBA2 antibody (A03816-2). SAE2/UBA2 was detected in paraffin-embedded section of human colon cance
A03816-2 · IHCIHC analysis of SAE2/UBA2 using anti-SAE2/UBA2 antibody (A03816-2). SAE2/UBA2 was detected in paraffin-embedded section of human mammary can
A03816-2 · IFIF analysis of SAE2/UBA2 using anti-SAE2/UBA2 antibody (A03816-2). SAE2/UBA2 was detected in immunocytochemical section of A431 cell. Enzyme
M03816-2 · IHCIHC analysis of SAE2/UBA2 using anti-SAE2/UBA2 antibody (M03816-2). SAE2/UBA2 was detected in paraffin-embedded section of human intestinal
M03816-2 · IHCIHC analysis of SAE2/UBA2 using anti-SAE2/UBA2 antibody (M03816-2). SAE2/UBA2 was detected in paraffin-embedded section of human intestinal
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000126261-UBA2/tissue/cerebral+cortex#imid_10756259
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000126261-UBA2/tissue/colon#imid_10756177
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000126261-UBA2/tissue/liver#imid_10756170
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000126261-UBA2/tissue/kidney#imid_10756171
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA041436; green = UBA2, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA041436; green = UBA2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for UBA2 IHC & IF
🧪Run adipose tissue first: adipocytes should stain (HPA: High in adipocytes). Run placenta as the negative tissue (HPA: Not detected in trophoblastic cells); on the adipose slide, any independently verified UBA2-negative stromal cells should show only background staining, since the supplied HPA rows do not establish an internal negative cell population.
Positive control tissue: Adipose tissue (Adipocytes, HPA High)
Negative control tissue: Placenta (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show UBA2 in A-431, U-251MG, U2OS, RPTEC/TERT1, hTERT-RPE1 (serum starved), with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include a no-primary secondary-only control, rabbit IgG matched to the primary antibody’s isotype and clonality, and UBA2-knockout material processed alongside the tissue (selected-SKU tissue-IHC caption: rabbit primary antibody; standard IHC practice). For chromogenic detection, block endogenous peroxidase and assess endogenous biotin background because the documented detection uses a streptavidin–biotin complex with DAB (selected-SKU tissue-IHC caption).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected-SKU tissue-IHC caption does not report a fixative. The caption uses citrate retrieval at pH 6 for 20 minutes, but does not establish that retrieval is required or that frozen sections or IF/ICC are easier (selected-SKU tissue-IHC caption). In adipose sections, lipid extraction can leave empty adipocyte vacuoles; assess staining in the remaining cellular rim and nuclei (standard paraffin IHC practice; HPA: High in adipocytes).
HPA tissue IHC evidence for UBA2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — 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 |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | High | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Breast | Adipocytes | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Placenta | Trophoblastic cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced UBA2 IHC Tips
Troubleshoot UBA2 staining in paraffin-section IHC by checking retrieval, compartment-specific signal, controls and scoring before interpreting differences between samples.
How should I retrieve UBA2 in paraffin sections when nuclear staining is weak?
Start with heat-mediated citrate buffer at pH 6 for 20 minutes (datasheet A03816-2). The selected paraffin-section image used this retrieval before overnight incubation at 4°C with 1 μg/mL catalog antibody (datasheet A03816-2). If nuclei remain weak, check heating consistency, section adhesion and whether the tissue has dried during processing (standard IHC practice). Compare any retrieval adjustment on adjacent sections while holding antibody concentration and detection conditions constant (standard IHC practice). Judge improvement by sharper nuclear staining with less diffuse background, using the reported predominantly nuclear pattern as a reference (HPA tissue IHC; standard IHC practice).
Could fixation explain inconsistent UBA2 staining across paraffin blocks?
The selected paraffin-section caption does not state a fixative, so UBA2-specific sensitivity to fixation is unknown (datasheet A03816-2). Record the fixative, fixation duration, block age and processing history for each specimen before comparing staining (standard IHC practice). Use the same citrate pH 6, 20-minute retrieval and matched detection conditions when testing adjacent sections (datasheet A03816-2; standard IHC practice). If a block stains poorly, assess tissue preservation and nuclear counterstain alongside antibody signal, then compare it with a well-preserved control processed in parallel (standard IHC practice). Do not assign a fixation effect from the observed HPA staining pattern alone (HPA tissue IHC).
Is cytoplasmic UBA2 staining plausible if the reference pattern is nuclear?
UBA2 can occur in both nucleus and cytoplasm and shuttles between them (UniProt Q9UBT2 subcellular location). Its HPA tissue-IHC profile is nuclear in essentially all cell types except placental trophoblasts, while HPA cell imaging places it mainly in the nucleoplasm (HPA tissue IHC; HPA subcellular). Assess nuclear and cytoplasmic DAB separately against the counterstain, avoiding a single whole-cell score (standard IHC practice). If cytoplasmic signal dominates, compare adjacent sections at lower primary concentration and inspect no-primary controls for diffuse chromogen deposition (standard IHC practice). A reproducible cytoplasmic component can be reported, but compartment alone does not establish a change in SUMO activation (UniProt Q9UBT2 function; standard IHC interpretation).
How do isoforms and modified residues affect interpretation of UBA2 IHC?
UniProt lists 2 UBA2 isoforms and several modified residues, including phosphoserines at positions 207, 507 and 592 (UniProt Q9UBT2 isoforms and modified residues). The supplied caption does not identify the antibody epitope or establish isoform-specific recognition (datasheet A03816-2). Therefore, treat DAB staining as antibody-reactive UBA2 signal rather than a measurement of one isoform or modification state (standard IHC interpretation). If samples differ, first compare retrieval, staining batch and nuclear versus cytoplasmic distribution under matched conditions (standard IHC practice). An isoform-specific conclusion requires independent evidence of epitope coverage and antibody selectivity (standard antibody-validation practice).
How can IF help check UBA2 localisation in the same tissue?
Use IF as a separate localisation check: HPA cell imaging reports UBA2 mainly in the nucleoplasm, while UniProt also records cytoplasmic localisation (HPA subcellular; UniProt Q9UBT2 subcellular location). Multiplex UBA2 with a validated marker for the cell type being assessed, such as an adipocyte marker when examining adipocytes, which HPA reports as strongly stained (HPA tissue IHC; standard IF practice). Choose spectrally separated fluorophores and consider a far-red channel if tissue autofluorescence obscures shorter wavelengths (standard IF practice). Because UBA2 is intracellular and has no transmembrane segment, permeabilise sufficiently for access to its nuclear or cytoplasmic epitope; the antibody's precise epitope is unspecified (UniProt Q9UBT2 topology and location; datasheet A03816-2). Include single-channel and secondary-only controls to assess bleed-through and background (standard IF practice).
What should I check when UBA2 DAB staining obscures nuclei?
The selected image used 10% goat serum blocking, a biotinylated secondary and streptavidin–biotin detection with DAB (datasheet A03816-2). With that detection route, check no-primary and secondary-only sections for nonspecific signal, and assess endogenous biotin where relevant (standard IHC practice). Apply a peroxidase block before DAB development and keep chromogen time consistent across the comparison set (standard chromogenic IHC practice). If nuclei are obscured, titrate the primary below the caption's 1 μg/mL condition or shorten development while retaining a positive control (datasheet A03816-2; standard IHC practice). Interpret weak diffuse color cautiously because the reference tissue pattern is predominantly nuclear (HPA tissue IHC).
How should I score UBA2 staining across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and score nuclear DAB intensity with the same thresholds across slides, because HPA describes broadly nuclear tissue expression (HPA tissue IHC; standard IHC practice). An H-score combines the percentages of cells at intensity 0–3 into a 0–300 scale; report percent positive cells alongside it (standard IHC scoring practice). If spatial distribution matters, report positive nuclei per mm² within a consistently defined tissue region (standard image-analysis practice). Normalise counts to evaluable cells or tissue area and exclude folds, edges and necrosis by a prespecified rule (standard IHC practice). Keep retrieval, detection and image-analysis settings matched, and score cytoplasmic signal separately if present (standard IHC practice).
When is UBA2 staining convincing rather than an IHC artefact?
A convincing result shows interpretable nuclear staining in preserved cells, consistent with HPA's predominantly nuclear tissue pattern and supported nucleoplasmic localisation (HPA tissue IHC; HPA subcellular). Placental trophoblasts are reported as not detected, so strong staining there warrants closer control review rather than automatic biological interpretation (HPA tissue IHC). Check whether signal tracks section edges, folds or necrotic areas, which can produce misleading chromogen patterns (standard IHC practice). Review no-primary and detection controls for endogenous peroxidase or other assay background, especially when DAB appears outside cells (standard IHC practice). Reproducibility across adjacent sections and a coherent nuclear counterstain strengthen interpretation, while staining alone does not measure SUMO E1 activity (standard IHC practice; UniProt Q9UBT2 function).
Boster reagents
Best UBA2 / SUMO-activating enzyme subunit 2 IHC Antibodies
Two anti-UBA2 antibodies have IHC images from human paraffin sections; A03816-2 also has mouse and rat testis IHC images and an A431 cell IF image (catalog image captions).
Real IHC data
Anti-SAE2/UBA2 Antibody ®
Cat # A03816-2
Real IHC data
Anti-SAE2/UBA2 Antibody ® (monoclonal, 5B13)
Cat # M03816-2
A03816-2 will render with a human colon cancer paraffin-section IHC figure; its catalog also documents human mammary cancer, mouse and rat testis IHC, and A431 cell IF (catalog image captions). M03816-2 will render with a human intestinal cancer paraffin-section IHC figure (catalog image caption).
Which to pick: For paraffin-section IHC, choose rabbit A03816-2 for the documented human, mouse and rat tissue examples, using citrate retrieval at pH 6 (A03816-2 IHC captions); mouse monoclonal M03816-2 has a human intestinal cancer example using EDTA retrieval at pH 8.0 (M03816-2 IHC caption). For IF/ICC, choose A03816-2: its application list includes both, and its A431 cell IF image used 2 μg/mL primary antibody (A03816-2 catalog applications and IF caption). Fixation is unreported in both paraffin-section IHC captions, so confirm fixation and optimize retrieval for the intended samples (A03816-2 and M03816-2 IHC captions; standard IHC practice).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9UBT2 (SAE2_HUMAN, SUMO-activating enzyme subunit 2).
- Human Protein Atlas. UBA2 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. UBA2 subcellular location (ICC-IF): Mainly localized to the nucleoplasm..
- Human Protein Atlas. UBA2 antibody validation summary (1 antibodies).
- UBA2 promotes proliferation of colorectal cancer. Molecular medicine reports 2018 — PMC6236309.
- Ubiquitin-like modifier activating enzyme 2 promotes cell migration and invasion through Wnt/β-catenin signaling in gastric cancer. World journal of gastroenterology 2018 — PMC6235804.
- Increased SUMO-activating enzyme SAE1/UBA2 promotes glycolysis and pathogenic behavior of rheumatoid fibroblast-like synoviocytes. JCI insight 2020 — PMC7526534.
- Knockdown of ubiquitin-like modifier-activating enzyme 2 promotes apoptosis of clear cell renal cell carcinoma cells. Cell death & disease 2021 — PMC8578554.
- PubMed PMID:9920803 — UniProt-cited evidence.
- PubMed PMID:10217437 — UniProt-cited evidence.
- PubMed PMID:10187858 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for UBA2 (SUMO-activating enzyme subunit 2). Expected localisation Nuclear in most tissue cell types (HPA tissue IHC). Antigen retrieval: Citrate pH 6 HIER, heat-mediated (datasheet A03816-2). Validated IHC antibody: A03816-2 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative Placenta. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colon cancer tissue; fixative not specified (datasheet A03816-2); 2. Fixation: Image fixative and duration unreported (datasheet A03816-2); 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: Citrate pH 6 , 20 min (datasheet A03816-2); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A03816-2); 8. Primary antibody: Rabbit anti-UBA2, 0.5-1μg/ml (datasheet A03816-2); 9. Primary incubation: Overnight at 4 °C (datasheet A03816-2). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Placental trophoblasts may lack signal (HPA tissue IHC); Isoform / epitope: 2 isoforms; epitope coverage is unknown (UniProt); Regulation: Low tissue specificity; stimulus effects unreported (HPA RNA specificity). Evidence: UniProt Q9UBT2, HPA tissue IHC · Supported, HPA ICC-IF · Mainly localized to the nucleoplasm., Datasheet A03816-2, PMC6236309, PMC6235804. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/UBA2/immunohistochemistry-ihc-guide.