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IDH2 / Isocitrate dehydrogenase [NADP], mitochondrial · IHC design guide
Design Immunohistochemistry for IDH2
Plan IDH2 staining in paraffin sections around the granular cytoplasmic pattern observed in tissue (HPA tissue IHC) and its mitochondrial location (UniProt). Compare cell types using matched controls; colon glandular cells provide a high-staining reference (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
IDH2 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 | Granular cytoplasm (HPA tissue IHC) | |
| Staining pattern | Granular cytoplasmic staining across multiple cell types (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet M00510-3) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Epididymis+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image M00510-3) | |
| Caveat | Colon glands stain high; smooth muscle cells are undetected (HPA tissue IHC) | |
| Regulation | No expression regulator annotated (UniProt) | |
| Isoform / epitope | 2 isoforms; mature chain spans 40–452; verify epitope (UniProt) |
Section 1
Recommended IDH2 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet: M00510-3) is accompanied by four published protocols using mutation-specific IDH2 antibodies (PMC7286791; PMC7429919; PMC3892385; PMC7721993).
| Sample | Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet M00510-3) |
| Fixation | Image fixative and duration unreported (datasheet M00510-3); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet M00510-3); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet M00510-3) |
| Primary antibody | Mouse monoclonal (clone 2H4) anti-IDH2, 2μg/ml (datasheet M00510-3) |
| Primary incubation | Overnight at 4 °C (datasheet M00510-3) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet M00510-3) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | IDH2-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: General cytoplasmic expression with a granular pattern. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval for the catalog antibody (datasheet: M00510-3). Follow each article’s retrieval conditions when using its mutation-specific antibody (cited PMC methods).
Section 2
What Is the Expected IDH2 Staining Pattern?
IDH2 is mitochondrial and has no transmembrane segment (UniProt P48735). In tissue IHC, expect granular cytoplasmic staining, including high signal in appendix and colon glandular cells, bronchial respiratory epithelium, and bone marrow hematopoietic cells (HPA: tissue IHC). HPA rates the tissue pattern Enhanced, while reporting medium consistency between staining and RNA expression (HPA: tissue IHC). Interpret intensity by cell type, not by whole-tissue label (HPA: tissue IHC).
| Granular cytoplasmic signal in appendix or colon glandular cells. | This matches the reported distribution and high staining level in those cells (HPA: tissue IHC). Mitochondrial localization supports a punctate or granular cytoplasmic interpretation (UniProt P48735; HPA: subcellular ICC-IF). |
| Predominantly nuclear or sharply plasma-membrane staining. | Treat this as a localization mismatch requiring verification, because IDH2 is mitochondrial and has no transmembrane segment (UniProt P48735; HPA: subcellular ICC-IF). Review morphology and detection controls before attributing it to IDH2 (general IHC practice). |
| Strong signal in liver cholangiocytes, ovarian stroma cells, or smooth muscle cells. | Those specified cell populations were reported as not detected (HPA: tissue IHC). Unexpected staining may reflect cross-reactivity, endogenous detection activity, or a technical difference; the HPA observations alone cannot identify the cause (HPA: tissue IHC; general IHC practice). |
| Uniform haze across cells and tissue spaces, with little cellular granularity. | The appearance is less consistent with the reported granular cytoplasmic pattern (HPA: tissue IHC). Check background controls and tissue morphology before scoring weak haze as IDH2 positive (general IHC practice). |
| No signal in appendix or colon glandular cells while tissue morphology is preserved. | These are high-staining cell populations in the HPA tissue set (HPA: tissue IHC). A blank result warrants a detection and tissue-control check; differences between antibodies or preparations can still affect whether that reference pattern is reproduced (HPA: tissue IHC; general IHC practice). |
💡Expected IDH2 appearanceCall a convincing positive granular cytoplasmic staining in the relevant cells, potentially high in appendix or colon glands (HPA: tissue IHC), consistent with mitochondrial localization (UniProt P48735); isolated nuclear, membrane-like, or cell-type-incongruent signal needs verification (UniProt P48735; HPA: tissue IHC).
| Cell-resolved tissue reference | HPA reports high staining in appendix, cervix, colon, and duodenum glandular cells, bronchial respiratory epithelial cells, and bone marrow hematopoietic cells; it reports cholangiocytes and ovarian stroma cells as not detected (HPA: tissue IHC). Compare like cell populations when selecting controls. |
| Localization and processing | IDH2 is mitochondrial, lacks a transmembrane segment, and has an annotated mature chain at residues 40–452 (UniProt P48735). These facts guide compartment interpretation but do not specify the antibody epitope or predict antigen-retrieval performance. |
| Evidence and antibody scope | HPA labels tissue IHC reliability Enhanced and notes medium consistency with RNA data (HPA: tissue IHC). Its listed rabbit polyclonal antibody, HPA007831, has Enhanced IHC and Supported ICC validation (HPA: antibodies). Those ratings describe the assessed evidence, not every antibody or specimen. |
| IF/ICC Q: What localization should an IF image show? | A: Mitochondrial staining is supported by HPA ICC-IF images from A-431, U-251MG, and U2OS, consistent with UniProt localization (HPA: subcellular ICC-IF; UniProt P48735). This supports a compartment check; the paraffin-section IHC pattern remains the primary reference here (HPA: tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Known high-staining glandular cells are blank. | The observed result conflicts with the HPA reference for appendix or colon glands, but does not by itself identify a failed step (HPA: tissue IHC). | Confirm the intended cell population and tissue preservation; review the IHC-validated antibody's stated IHC-P conditions and run an appropriate positive control (general IHC practice). |
| Signal is diffuse throughout cytoplasm without visible granularity. | That pattern is less specific than HPA's general granular cytoplasmic description; diffuse background is one possibility (HPA: tissue IHC; general IHC practice). | Check a no-primary control, blocking, washes, and detection conditions; score localization only where cellular detail remains clear (general IHC practice). |
| Nuclei dominate the chromogenic signal. | Nuclear dominance disagrees with mitochondrial localization (UniProt P48735; HPA: subcellular ICC-IF). Counterstain overlap or nonspecific detection may complicate interpretation (general IHC practice). | Compare with the no-primary control and inspect whether granular cytoplasmic signal is independently visible before calling cells positive (general IHC practice). |
| A cell population reported as not detected stains strongly. | For example, cholangiocytes are listed as not detected, so strong signal needs review; HPA does not establish its mechanism (HPA: tissue IHC). | Verify cell identity, inspect a no-primary control for endogenous detection activity, and compare a known high-staining population on the same run (HPA: tissue IHC; general IHC practice). |
| Color develops broadly, including outside identifiable cells. | A widespread reaction can arise from detection-system background or endogenous activity (general IHC practice); it does not resemble HPA's cellular granular pattern (HPA: tissue IHC). | Review no-primary and detection controls, blocking, and wash steps; do not assign extracellular color to IDH2 (general IHC practice). |
| The chosen reference tissue gives mixed positive and negative cells. | HPA levels are attached to specified cell types, and its tissue summary describes general rather than universal cytoplasmic expression (HPA: tissue IHC). | Score the annotated cell population separately and compare its location and intensity with the relevant HPA entry; avoid treating the entire section as one control (HPA: tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing IDH2 staining
M00510-3 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (M00510-3). IDH2 was detected in paraffin-embedded section of human lung cancer tissue. Heat m
M00510-3 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (M00510-3). IDH2 was detected in paraffin-embedded section of human melanoma tissue. Heat medi
M00510-4 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (M00510-4). IDH2 was detected in paraffin-embedded section of human testicular cancer tissue.
M00510-4 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (M00510-4). IDH2 was detected in paraffin-embedded section of human rectal cancer tissue. Heat
M00510-4 · IFIF analysis of IDH2 using anti-IDH2 antibody (M00510-4). IDH2 was detected in immunocytochemical section of A431 cells. Enzyme antigen retri
PB9602 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (PB9602). IDH2 was detected in a paraffin-embedded section of human colon cancer tissue. Heat
PB9602 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (PB9602). IDH2 was detected in a paraffin-embedded section of human ovarican cancer tissue. He
PB9602 · IFIF analysis of IDH2 using anti-IDH2 antibody (PB9602). IDH2 was detected in an immunocytochemical section of A549 cells. Enzyme antigen retr
M00510 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (M00510). IDH2 was detected in a paraffin-embedded section of human colon cancer tissue. Heat
M00510 · IHCIHC analysis of IDH2 using anti-IDH2 antibody (M00510). IDH2 was detected in a paraffin-embedded section of human colon cancer tissue. Heat
A00510 · IHCImmunohistochemistry of IDH2 in mouse heart tissue with IDH2 antibody at 5 μg/mL.
A00510 · IFImmunofluorescence of IDH2 in mouse heart tissue with IDH2 antibody at 20 μg/mL.
M00510-2 · IFIF analysis of IDH2 using anti-IDH2 antibody (M00510-2). IDH2 was detected in immunocytochemical section of A431 cells. Enzyme antigen retri
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000182054-IDH2/tissue/cerebral+cortex#imid_2357292
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000182054-IDH2/tissue/colon#imid_2357218
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000182054-IDH2/tissue/liver#imid_2357227
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000182054-IDH2/tissue/kidney#imid_2357220
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA007831; green = IDH2, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA007831; green = IDH2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for IDH2 IHC & IF
🧪Run appendix first and assess staining in glandular cells (High; HPA: appendix glandular cells). Use epididymis glandular cells as a negative comparator (Not detected; HPA: epididymis glandular cells); no cell population within the appendix slide is documented here as IDH2-negative, so unstained cells there can serve only as a background reference.
Positive control tissue: Appendix (Glandular cells, HPA High)
Negative control tissue: Epididymis (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show IDH2 in A-431, U-251MG, U2OS, with annotated localisation: Mitochondria (supported) (HPA subcellular).
Technical controls: Include no-primary (secondary-only) and concentration-matched mouse IgG isotype controls, alongside an IDH2-knockout biological control where available (selected caption: mouse primary antibody). For the appendix slide, block endogenous peroxidase and assess endogenous biotin background before interpreting DAB staining with the biotin-based detection system (selected caption: biotinylated secondary, SABC and DAB).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected tissue-IHC caption does not state the fixative (selected caption: fixative unreported). The demonstrated paraffin-section workflow used heat retrieval in EDTA, pH 8.0, but the evidence does not establish that retrieval is required or that frozen sections are easier (selected caption: EDTA heat retrieval). IF/ICC images exist for A-431, U-251MG and U2OS, with mitochondrial localization supported, but the supplied evidence does not establish whether IF is easier than IHC; biotin-based DAB background is a practical artefact to check in the appendix control (HPA: subcellular; selected caption: SABC and DAB).
HPA tissue IHC evidence for IDH2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — 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 |
|---|---|---|---|---|
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Cerebellum | GLUC cells - cytoplasm/membrane | High | Protein (IHC) | HPA → |
| Cervix | Glandular cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Epididymis | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Liver | Cholangiocytes | Not detected | Protein (IHC) | HPA → |
| Ovary | Ovarian stroma cells | Not detected | Protein (IHC) | HPA → |
| Smooth muscle | Smooth muscle cells | Not detected | Protein (IHC) | HPA → |
| Spleen | Cells in red pulp | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced IDH2 IHC Tips
Troubleshoot IDH2 staining by checking retrieval, cell compartment and background before comparing signal across paraffin sections (UniProt P48735; HPA tissue IHC).
What should I change when IDH2 staining is weak after antigen retrieval?
Start with heat-mediated retrieval in EDTA pH 8.0 for paraffin sections (datasheet M00510-3). The documented tissue example then used 10% goat serum block and 2 μg/mL primary antibody overnight at 4°C (caption M00510-3). If signal remains weak, compare a modestly longer heating interval on matched sections while keeping antibody concentration and detection constant (standard IHC practice). Check that glandular or respiratory epithelial cells expected to stain are present before judging retrieval failure (HPA: High in appendix glandular cells and bronchus respiratory epithelial cells). Excess heating can damage morphology, so assess staining and tissue preservation together (standard IHC practice).
How should I troubleshoot IDH2 staining when fixation history is uncertain?
The selected tissue caption identifies a paraffin-embedded section but does not state its fixative, so target-specific fixation sensitivity is unknown (caption M00510-3). Record the fixative, fixation duration and processing history for each specimen, then compare sections processed alike before adjusting retrieval or antibody concentration (standard IHC practice). Use the documented EDTA pH 8.0 heat retrieval and 2 μg/mL primary incubation as starting conditions for this antibody (caption M00510-3). If staining differs across processing batches, include an identically processed positive control and inspect morphology; a batch effect alone does not establish how fixation affects IDH2 (standard IHC practice).
Should IDH2 stain nuclei or show diffuse cytoplasmic signal?
Expect a granular cytoplasmic pattern in tissue sections (HPA: general cytoplasmic expression with a granular pattern). This agrees with mitochondrial localisation (UniProt P48735: mitochondrion; HPA subcellular: mitochondria supported). Score staining within the intended cell population and compare granularity with an appropriate mitochondrial marker on an adjacent section when the compartment is ambiguous (standard IHC practice). Predominantly nuclear or uniform extracellular DAB warrants a review of counterstain, background and detection controls before being called IDH2 (standard IHC practice; UniProt P48735: mitochondrion). Keep the EDTA pH 8.0 retrieval condition consistent during this comparison (caption M00510-3).
Can this antibody distinguish IDH2 isoforms or processing states in tissue?
IDH2 has 2 annotated isoforms, and the processed chain spans residues 40–452 (UniProt P48735). The supplied caption does not identify this antibody’s epitope or establish isoform selectivity, so total staining should not be assigned to a particular isoform (caption M00510-3). IDH2 also has annotated acetylated residues, including positions 45 and 48, but the supplied evidence does not show whether those modifications alter recognition (UniProt P48735). If an isoform or modification claim matters, establish epitope coverage and test specificity with appropriate controls before interpreting differences in chromogenic signal (standard IHC practice).
How can I adapt the IDH2 localisation check to multiplex IF?
Treat IF as a separate assay: the supplied tissue protocol documents chromogenic staining of a paraffin section, while HPA reports mitochondrial ICC/IF localisation (caption M00510-3; HPA subcellular: mitochondria supported). Pair IDH2 with a marker for the cell population being evaluated and, when needed, a mitochondrial marker to assess signal overlap (standard IF practice; UniProt P48735: mitochondrion). Choose fluorophores after checking tissue autofluorescence, favoring a spectrally separated, longer-wavelength channel for a weak target (standard IF practice). For intracellular mitochondrial epitopes, optimise permeabilisation to allow antibody access across cellular and mitochondrial membranes while preserving morphology; epitope accessibility for this antibody is unreported (standard IF practice; UniProt P48735: no transmembrane segment).
How do I reduce diffuse brown staining without losing granular IDH2 signal?
Begin with the documented 10% goat serum block and 2 μg/mL primary antibody, then compare matched sections with and without primary antibody (caption M00510-3; standard IHC practice). The selected example used a biotinylated secondary, avidin–biotin detection and DAB, so assess nonspecific secondary binding and endogenous biotin in the tissue being tested (caption M00510-3; standard IHC practice). Apply a peroxidase block before DAB development and control chromogen development time on matched sections (standard chromogenic IHC practice). Preserve granular cytoplasmic staining when optimising washes or antibody concentration; widespread staining outside cells is inconsistent with the expected pattern (HPA: granular cytoplasmic expression).
What should I measure when comparing IDH2 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population first, then record the percentage of positive cells and staining intensity with an H-score, or quantify DAB-positive area per mm² where segmentation is reliable (standard IHC practice). Normalise to the number or area of evaluable target cells, rather than total section area, and apply one threshold and exposure-independent analysis workflow across slides (standard IHC practice). Exclude folds, necrosis and section edges before scoring, and report the amount excluded (standard IHC practice). Retain the granular cytoplasmic pattern as a localisation check, because intensity alone cannot distinguish plausible IDH2 staining from background (HPA: granular cytoplasmic expression; UniProt P48735: mitochondrion).
When is an apparent IDH2-positive cell likely an artefact?
A convincing result places granular cytoplasmic signal inside the scored cells, consistent with mitochondrial IDH2 (HPA: granular cytoplasmic expression; UniProt P48735: mitochondrion). Compare cell identity with the section: HPA reports High staining in bronchus respiratory epithelial cells and Not detected staining in liver cholangiocytes, so these populations should not be treated as interchangeable controls (HPA tissue IHC). Nuclear-only signal, necrotic debris and staining concentrated at section edges warrant closer inspection before scoring (standard IHC practice). Check a no-primary control for residual DAB from endogenous peroxidase and repeat uncertain findings in a matched section; the selected assay uses DAB detection (standard IHC practice; caption M00510-3).
Boster reagents
Best IDH2 / Isocitrate dehydrogenase [NADP], mitochondrial IHC Antibodies
Anti-IDH2 antibodies have IHC images from human cancer sections and mouse heart, plus IF images from A431 cells, A549 cells, and mouse heart (catalog image captions).
Real IHC data
Anti-IDH2 Antibody ® (monoclonal, 2H4)
Cat # M00510-3
Real IHC data
Anti-IDH2 Antibody ® (monoclonal, 6B13)
Cat # M00510-4
Real IHC data
Anti-IDH2 Antibody ®
Cat # PB9602
Real IHC data
Anti-IDH2 Monoclonal Antibody
Cat # M00510
Real IHC data
Anti-IDH2 Antibody
Cat # A00510
Real IF data
Anti-IDH2 Antibody ® (monoclonal, 2D4)
Cat # M00510-2
M00510-3 has IHC images from human lung cancer sections, M00510-4 from human testicular cancer sections, PB9602 and M00510 from human colon cancer sections, and A00510 from mouse heart (each SKU’s IHC image caption). M00510-2 has an IF image from A431 cells (M00510-2 IF image caption); M00510-4 also has an A431 IF image, PB9602 has an A549 IF image, and A00510 has a mouse heart IF image (each SKU’s IF image caption).
Which to pick: For tissue IHC, PB9602 is a useful starting choice because its own images show paraffin sections of human colon cancer and mouse and rat heart (PB9602 IHC image captions). For IF/ICC, choose M00510-2 for its A431 cell IF example (M00510-2 IF image caption), or M00510-4 if both IHC and IF/ICC are needed (M00510-4 application list and image captions). For work across the three listed species, PB9602 has human, mouse, and rat IHC images (PB9602 IHC image captions); its paraffin section captions specify EDTA pH 8.0 retrieval, but do not report the fixative (PB9602 IHC image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P48735 (IDHP_HUMAN, Isocitrate dehydrogenase [NADP], mitochondrial).
- Human Protein Atlas. IDH2 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. IDH2 subcellular location (ICC-IF): Localized to the mitochondria..
- Human Protein Atlas. IDH2 antibody validation summary (1 antibodies).
- Immunohistochemical analysis of IDH2 R172 hotspot mutations in breast papillary neoplasms: applications in the diagnosis of tall cell carcinoma with reverse polarity. Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2020 — PMC7286791.
- The role of a monoclonal antibody 11C8B1 as a diagnostic marker of IDH2-mutated sinonasal undifferentiated carcinoma. Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2019 — PMC7429919.
- Isocitrate dehydrogenase 2 mutation is a frequent event in osteosarcoma detected by a multi-specific monoclonal antibody MsMab-1. Cancer medicine 2013 — PMC3892385.
- Molecular epidemiology of IDH2 hotspot mutations in cancer and immunohistochemical detection of R172K, R172G, and R172M variants. Human pathology 2020 — PMC7721993.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:16572171 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for IDH2 (Isocitrate dehydrogenase [NADP], mitochondrial). Expected localisation Granular cytoplasm (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet M00510-3). Validated IHC antibody: M00510-3 at 2μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative Epididymis. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet M00510-3); 2. Fixation: Image fixative and duration unreported (datasheet M00510-3); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet M00510-3); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet M00510-3); 8. Primary antibody: Mouse monoclonal (clone 2H4) anti-IDH2, 2μg/ml (datasheet M00510-3); 9. Primary incubation: Overnight at 4 °C (datasheet M00510-3). Watch for: Fixation: Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image M00510-3); Caveat: Colon glands stain high; smooth muscle cells are undetected (HPA tissue IHC); Isoform / epitope: 2 isoforms; mature chain spans 40–452 ; verify epitope (UniProt); Regulation: No expression regulator annotated (UniProt). Evidence: UniProt P48735, HPA tissue IHC · Enhanced, HPA ICC-IF · mitochondria., Datasheet M00510-3, PMC7286791, PMC7429919. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/IDH2/immunohistochemistry-ihc-guide.