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MFN2 / Mitofusin-2 · IHC design guide
Design Immunohistochemistry for MFN2
Plan chromogenic MFN2 IHC in paraffin sections using the catalog antibody at 5 μg/mL (datasheet: 5 μg/mL). Interpret mainly cytoplasmic tissue staining (HPA tissue IHC) in light of MFN2’s outer mitochondrial membrane location (UniProt) and uncertain agreement between staining and RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
MFN2 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 | IHC mainly cytoplasmic (HPA tissue IHC); outer mitochondrial membrane (UniProt) | |
| Staining pattern | Mainly cytoplasmic staining in most tissues (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Cerebellum+4 more · see all | |
| Negative control | Liver+2 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). Selected-image fixative and duration unreported (datasheet A00461); verify before use. | |
| Caveat | Staining has low consistency with RNA expression (HPA tissue IHC) | |
| Regulation | Higher expression in heart and kidney (UniProt) | |
| Isoform / epitope | 2 isoforms; epitope differences unspecified (UniProt) |
Section 1
Recommended MFN2 IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol with published MFN2 staining methods for tissue sections, hepatocellular carcinoma, and bladder cancer (PMC6038474; PMC4892862; PMC6676712).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet A00461); 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 citrate buffer, pH 6.0, 20 min at 95–98 °C (standard rule: cytoplasmic / membrane 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-MFN2, 5 μg/mL (datasheet A00461) |
| 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 | MFN2-positive staining in purkinje cells of cerebellum (HPA tissue IHC: High). HPA tissue profile: Mainly cytoplasmic expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 retrieval at 95–98 °C for 20 min (page retrieval); published protocols also use pH 7.5 or longer heating (PMC4892862; PMC6676712).
Section 2
What Is the Expected MFN2 Staining Pattern?
MFN2 is on the mitochondrial outer membrane, with cytoplasmic regions (UniProt O95140 topology). In paraffin IHC, HPA reports mainly cytoplasmic staining, including high staining in kidney tubules and Purkinje cells; its tissue IHC reliability is uncertain (HPA tissue IHC).
| Cytoplasmic staining in kidney tubules (HPA tissue IHC). | Consistent with HPA's high tubular staining and mainly cytoplasmic profile (HPA tissue IHC). |
| Predominantly nuclear staining. | Unexpected for outer mitochondrial membrane MFN2; assess artefact (UniProt O95140 topology). |
| Strong staining in liver cholangiocytes (HPA: not detected). | Check cross-reactivity or endogenous detection activity (standard IHC practice). |
| Diffuse staining across tissue and blank areas. | Suggests background; inspect blocking and detection controls (standard IHC practice). |
| No staining in kidney tubules (HPA: High). | Unexpected, though HPA tissue IHC reliability is uncertain (HPA tissue IHC). |
💡Expected MFN2 appearanceA positive result shows cytoplasmic staining in kidney tubules or Purkinje cells (HPA: High); dominant nuclear or blank-area staining warrants investigation (UniProt O95140 topology; standard IHC practice).
| Membrane topology (UniProt O95140). | Both N- and C-terminal regions face cytoplasm; the antibody epitope is unspecified (UniProt O95140 topology). |
| Tissue variation (HPA tissue IHC). | Kidney tubules stain High; liver cholangiocytes are not detected (HPA tissue IHC). |
| IHC evidence (HPA antibodies; HPA tissue IHC). | HPA030554 IHC is Uncertain; tissue staining has low RNA consistency (HPA antibodies; HPA tissue IHC). |
| Isoforms (UniProt O95140). | Two isoforms are recorded; this staining alone cannot distinguish them (UniProt O95140 isoforms). |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in kidney tubules (HPA: High). | Assay failure is possible; HPA tissue IHC reliability is uncertain (HPA tissue IHC). | Review positive control, retrieval and antibody dilution (standard IHC practice). |
| Predominantly nuclear signal. | Location conflicts with MFN2 membrane topology (UniProt O95140 topology). | Check antibody specificity and detection controls (standard IHC practice). |
| Strong signal in cholangiocytes (HPA: not detected). | Cross-reactivity or endogenous activity is possible (standard IHC practice). | Run a no-primary control and review blocking (standard IHC practice). |
| Diffuse tissue and blank-area staining. | Background from detection or inadequate blocking is possible (standard IHC practice). | Inspect no-primary control and optimize blocking (standard IHC practice). |
| Variable staining between tissues (HPA tissue IHC). | HPA reports cell-level variation and uncertain IHC reliability (HPA tissue IHC). | Compare matched cell types and controls (standard IHC practice). |
| IF/ICC: where should MFN2 appear? | Mitochondrial localization is supported (HPA subcellular ICC-IF). | Assess mitochondrial localization; U2OS images are available (HPA subcellular ICC-IF). |
Experiment evidence
IHC & IF images showing MFN2 staining
A00461 · IHCImmunohistochemistry of MFN2 in rat brain tissue with MFN2 antibody at 5 μg/mL.
A00461 · IHCImmunohistochemistry of MFN2 in mouse brain tissue with MFN2 antibody at 5 μg/mL.
A00461 · IFImmunofluorescence of MFN2 in rat brain tissue with MFN2 antibody at 20 μg/mL.
M00461 · IHCImmunohistochemical analysis of paraffin-embedded human breast carcinoma, using Mitofusin 2 Antibody.
M00461 · IFImmunofluorescent analysis of Hela cells, using Mitofusin 2 Antibody.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000116688-MFN2/tissue/cerebral+cortex#imid_8031911
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000116688-MFN2/tissue/colon#imid_8031845
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000116688-MFN2/tissue/liver#imid_8031854
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000116688-MFN2/tissue/kidney#imid_8031847
HPA · ICC-IF U2OSHuman Protein Atlas immunofluorescence, U2OS, antibody CAB079902; green = MFN2, blue = nucleus, red = microtubules.
HPA · ICC-IF U2OSHuman Protein Atlas immunofluorescence, U2OS, antibody CAB079902; green = MFN2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for MFN2 IHC & IF
🧪Run kidney first: cells in tubules should stain (HPA: High in kidney cells in tubules). Use liver cholangiocytes as the biological reference with no detected staining (HPA: Not detected in liver cholangiocytes); on the kidney slide, cells without specific signal should show counterstain and background only, but no named kidney cell type is established as MFN2-negative by these data (HPA: High in kidney cells in tubules; UniProt O95140: ubiquitous, low expression).
Positive control tissue: Cerebellum (Purkinje cells, HPA High)
Negative control tissue: Liver (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show MFN2 in U2OS, with annotated localisation: Mitochondria (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host species and clonality (standard IHC practice); use MFN2-knockout material or an immunizing-peptide block, if available, to assess target specificity (standard IHC practice). For chromogenic kidney IHC, quench endogenous peroxidase and, if using biotin-based detection, control for endogenous biotin (standard IHC practice).
⚠️Feasibility: A target-specific fixation window, fixation effect, and antigen-retrieval dependency are unreported in the supplied evidence; optimize retrieval with the IHC-validated antibody using standard paraffin-section practice. The selected tissue-IHC caption reports rat brain staining at 5 μg/mL, but its fixative is unreported (selected SKU A00461 caption). ICC-IF provides a supported mitochondrial localization reference in U2OS cells (HPA: mitochondria, supported; U2OS ICC-IF images), but the supplied evidence does not establish whether IF or frozen sections are easier than paraffin IHC; kidney sections require attention to endogenous peroxidase and, with biotin-based detection, endogenous biotin (standard IHC practice).
HPA tissue IHC evidence for MFN2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — Low 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 |
|---|---|---|---|---|
| Cerebellum | Purkinje cells | High | Protein (IHC) | HPA → |
| Cerebral cortex | Neuronal cells | High | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | High | Protein (IHC) | HPA → |
| Kidney | Cells in tubules | High | Protein (IHC) | HPA → |
| Lymph node | Non-germinal center cells | High | Protein (IHC) | HPA → |
Section 3
Advanced MFN2 IHC Tips
Troubleshoot MFN2 staining in paraffin sections with chromogenic IHC, using its mitochondrial location and the supplied tissue evidence to guide controls.
How should I optimize retrieval when MFN2 staining is weak?
Start with citrate buffer at pH 6.0 for heat-induced epitope retrieval at 95–98 °C for 20 min (page retrieval specification). If staining remains weak, compare a shorter or longer retrieval time on adjacent sections while keeping the buffer and detection conditions fixed, and check whether tissue morphology deteriorates (standard IHC practice). The catalog antibody has a rat brain tissue-IHC image at 5 µg/mL, but its caption does not report the fixative or retrieval method (A00461 caption). Score signal in cellular cytoplasm rather than nuclei, because MFN2 resides on the mitochondrial outer membrane (UniProt O95140 topology; HPA subcellular).
Could fixation explain weak or uneven MFN2 staining?
MFN2-specific sensitivity to fixation is unknown from the supplied evidence; the rat brain image caption gives an antibody concentration of 5 µg/mL but no fixative (A00461 caption). For paraffin-section IHC, record fixation type and duration, then compare sections processed with matched retrieval, antibody concentration, and detection settings (standard IHC practice). Overfixation and underfixation can each compromise interpretable staining, so inspect morphology alongside signal before changing retrieval or antibody concentration (standard IHC practice). Keep a consistently processed positive control in each run, and avoid attributing differences between samples to MFN2 abundance until processing variation has been checked (standard IHC practice).
What staining pattern should count as correctly localised MFN2?
Expect MFN2 signal in the cytoplasmic mitochondrial compartment, consistent with its outer-membrane location and HPA’s mainly cytoplasmic tissue-IHC profile (UniProt O95140 subcellular; HPA tissue IHC). Its 2 transmembrane segments span residues 605–625 and 627–647, leaving most of the protein on the cytoplasmic side (UniProt O95140 topology). Assess staining within intact cells and compare its distribution with a mitochondrial marker on a serial section or by the companion IF workflow (standard IHC practice). Predominantly nuclear or diffuse extracellular chromogen warrants a review of background, tissue preservation, and antibody specificity before biological interpretation (UniProt O95140 subcellular; standard IHC practice).
How can epitope position affect MFN2 staining in paraffin sections?
MFN2 has 2 reported isoforms, but the supplied catalog caption does not identify the antibody epitope or establish isoform selectivity (UniProt O95140 isoforms; A00461 caption). Map the immunogen against both isoforms before interpreting a negative section as loss of all MFN2 protein (UniProt O95140 isoforms; standard IHC practice). Epitope accessibility may also vary after fixation and retrieval, so compare adjacent sections under matched processing conditions before changing the detection system (standard IHC practice). MFN2 has cytoplasmic regions at residues 1–604 and 648–757, with reported PINK1 phosphorylation at 111 and 442; these annotations alone do not establish antibody sensitivity to phosphorylation (UniProt O95140 topology and modified residues).
How can IF help verify MFN2 localisation seen by chromogenic IHC?
On the separate IF/ICC guide workflow, multiplex MFN2 with a mitochondrial marker and a marker identifying the expected cell type, then compare patterns within individual cells (HPA subcellular; standard IF practice). Choose fluorophores after checking tissue autofluorescence in an unstained control, favouring channels with a clear signal above that background (standard IF practice). Match permeabilisation to the mapped antibody epitope: most MFN2 residues face the cytoplasm, whereas residue 626 faces the mitochondrial intermembrane space (UniProt O95140 topology). Because the catalog caption documents tissue IHC rather than IF, validate the antibody’s IF signal and include appropriate single-stain controls before using colocalisation to support an IHC result (A00461 caption; standard IF practice).
How do I separate MFN2 signal from chromogenic background?
Inspect a no-primary control alongside each staining run to reveal secondary-reagent, endogenous-enzyme, or tissue-pigment contributions (standard IHC practice). For peroxidase-based detection, include a peroxidase block and evaluate DAB deposition against that control; these are general chromogenic workflow steps, not MFN2-specific validation (standard IHC practice). Compare antibody titration and wash conditions on adjacent sections, including the catalog image concentration of 5 µg/mL as a documented reference rather than a universally optimal dose (A00461 caption; standard IHC practice). Treat diffuse extracellular staining or strong section-edge colour with caution, since MFN2 is assigned to mitochondria and tissue IHC is mainly cytoplasmic (UniProt O95140 subcellular; HPA tissue IHC).
How should I score MFN2 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring: MFN2 is mitochondrial, and the reported tissue-IHC pattern is mainly cytoplasmic (UniProt O95140 subcellular; HPA tissue IHC). For comparable regions, record the percentage of positive cells and intensity, then calculate an H-score from the proportion at each intensity level (standard IHC practice). If measuring stained area or positive-cell density per mm², normalise to viable tissue area or the number of eligible cells, respectively, and exclude folds and necrosis (standard IHC practice). Keep staining batches, imaging settings, thresholds, and observer rules consistent; report these choices because HPA rates its MFN2 tissue-IHC reliability as uncertain (standard IHC practice; HPA tissue IHC).
When is an apparent MFN2-positive cell likely to be an artefact?
Give greatest weight to staining within intact-cell cytoplasm, where a mitochondrial outer-membrane protein belongs, and question dominant nuclear or extracellular signal (UniProt O95140 subcellular; HPA tissue IHC). Compare the apparent cell type with documented high-staining examples such as cerebellar Purkinje cells, cerebral-cortex neuronal cells, and kidney tubule cells, while recognising that HPA labels its tissue-IHC reliability uncertain (HPA tissue IHC). Check section edges and necrotic regions for uneven chromogen, and review the no-primary control for endogenous enzyme or detection background before calling an unexpected positive (standard IHC practice). A negative result also needs caution: HPA reports low consistency between antibody staining and RNA expression, so confirm it with a well-processed positive control (HPA tissue IHC; standard IHC practice).
Boster reagents
Best MFN2 / Mitofusin-2 IHC Antibodies
Anti-MFN2 antibodies have IHC images from rat and mouse brain and human breast carcinoma, plus IF images from rat and mouse brain and HeLa cells (catalog image captions).
Real IHC data
Anti-Mitofusin-2 MFN2 Antibody
Cat # A00461
Real IHC data
Anti-Mitofusin 2 MFN2 Rabbit Monoclonal Antibody
Cat # M00461
A00461 has IHC images from rat and mouse brain and IF images from rat and mouse brain (catalog image captions). M00461 has an IHC image from paraffin-embedded human breast carcinoma and an IF image from HeLa cells (catalog image captions).
Which to pick: For paraffin-section tissue IHC, choose M00461 when its human breast carcinoma example is relevant (M00461 IHC caption); its fixative is unreported (M00461 IHC caption). For IF/ICC, M00461 lists both applications and is a rabbit monoclonal, while A00461 lists IF and has rat and mouse brain IF images (catalog applications; catalog host and clone; A00461 IF captions). For cross-species IHC, both list human, mouse and rat reactivity; A00461 shows rat and mouse brain IHC, while M00461 shows human breast carcinoma IHC (catalog reactivity; IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry O95140 (MFN2_HUMAN, Mitofusin-2).
- Human Protein Atlas. MFN2 tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. MFN2 subcellular location (ICC-IF): Localized to the mitochondria..
- Human Protein Atlas. MFN2 antibody validation summary (2 antibodies).
- Mitofusin2 Induces Cell Autophagy of Pancreatic Cancer through Inhibiting the PI3K/Akt/mTOR Signaling Pathway. Oxidative medicine and cellular longevity 2018 — PMC6038474.
- Prognostic impact of mitofusin 2 expression in colon cancer. Translational cancer research 2022 — PMC9641083.
- The evaluative value of Sema3C and MFN2 co-expression detected by immunohistochemistry for prognosis in hepatocellular carcinoma patients after hepatectomy. OncoTargets and therapy 2016 — PMC4892862.
- Mitofusin 2 inhibits bladder cancer cell proliferation and invasion via the Wnt/β-catenin pathway. Oncology letters 2019 — PMC6676712.
- PubMed PMID:12598526 — UniProt-cited evidence.
- PubMed PMID:15322553 — UniProt-cited evidence.
- PubMed PMID:9039502 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for MFN2 (Mitofusin-2). Expected localisation IHC mainly cytoplasmic (HPA tissue IHC); outer mitochondrial membrane (UniProt). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A00461 at 5 μg/mL (the product's own IHC validation image is shown). Controls (HPA): positive Cerebellum (Purkinje cells); negative Liver. 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 A00461); 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 citrate buffer, pH 6.0 , 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-MFN2, 5 μg/mL (datasheet A00461); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific). Selected-image fixative and duration unreported (datasheet A00461); verify before use.; Caveat: Staining has low consistency with RNA expression (HPA tissue IHC); Isoform / epitope: 2 isoforms; epitope differences unspecified (UniProt); Regulation: Higher expression in heart and kidney (UniProt). Evidence: UniProt O95140, HPA tissue IHC · Uncertain, HPA ICC-IF · mitochondria., Datasheet A00461, PMC6038474, PMC4892862. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/MFN2/immunohistochemistry-ihc-guide.