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MT-CO2 / Cytochrome c oxidase subunit 2 · IHC design guide
Design Immunohistochemistry for MT-CO2
Plan MT-CO2 chromogenic IHC in paraffin sections using granular cytoplasmic staining as the tissue readout (HPA tissue IHC). Start with the IHC-validated antibody at 2–5 μg/ml (datasheet A03631-1) and use adrenal gland glandular cells as a high-staining reference (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
MT-CO2 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 observed (HPA tissue IHC); inner mitochondrial membrane expected (UniProt) | |
| Staining pattern | Ubiquitous granular cytoplasmic staining (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A03631-1) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | None in HPA (detected in all 45 tissues); use no-primary + isotype controls |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep paraffin-section fixation consistent across samples (standard IHC practice; not target-specific) | |
| Caveat | Ubiquitous staining limits cell-type discrimination (HPA tissue IHC) | |
| Regulation | No expression regulator annotated (UniProt) | |
| Isoform / epitope | No annotated isoforms or cleavage; epitope position matters (UniProt) |
Section 1
Recommended MT-CO2 IHC & IF Protocols
Start with the catalog antibody’s IHC-P protocol (datasheet: A03631-1), then compare the published MT-CO2 IHC methods below (PMC11695821; PMC4170973; PMC12508156).
| Sample | Paraffin-embedded human colorectal cancer tissue; fixative not specified (datasheet A03631-1) |
| Fixation | Image fixative and duration unreported (datasheet A03631-1); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A03631-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A03631-1) |
| Primary antibody | Rabbit anti-MT-CO2, 2-5 μg/ml (datasheet A03631-1) |
| Primary incubation | Overnight at 4 °C (datasheet A03631-1) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A03631-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | MT-CO2-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Ubiquitous cytoplasmic expression with a granular pattern. No signal in the no-primary control. |
💡Decision noteTry heat-mediated EDTA pH 8.0 first for the catalog antibody (datasheet: A03631-1); published antibody protocols used other retrieval buffers (PMC11695821; PMC4170973; PMC12508156).
Section 2
What Is the Expected MT-CO2 Staining Pattern?
MT-CO2 is an inner mitochondrial membrane protein with two transmembrane segments (UniProt P00403 topology). In paraffin tissue IHC, expect granular cytoplasmic staining across many cell types (HPA: ubiquitous cytoplasmic granular pattern; tissue reliability Enhanced). HPA reports high staining in adrenal glandular cells, bronchial respiratory epithelial cells and cerebral cortex neurons, among others (HPA tissue IHC).
| Granular cytoplasmic staining in adrenal glandular cells or bronchial respiratory epithelial cells (HPA tissue IHC). | This fits the reported High staining in both cell populations (HPA tissue IHC) and the expected mitochondrial compartment (UniProt P00403 topology). Assess the granules within cells against the counterstain and a matched negative control (general IHC practice). |
| Strong, predominantly nuclear staining or a continuous cell-surface outline. | Neither pattern fits the inner mitochondrial membrane location (UniProt P00403 topology) or HPA's granular cytoplasmic tissue pattern (HPA tissue IHC). Treat it as suspect; review morphology, antibody specificity and detection controls before assigning it to MT-CO2 (general IHC practice). |
| Adipocytes dominate the signal while the expected granular pattern is weak elsewhere. | HPA reports Low staining in adipocytes, so dominant adipocyte signal warrants a specificity check (HPA tissue IHC). Because HPA describes broad tissue expression, staining in an unlisted cell type alone does not establish cross-reactivity; compare compartment and controls (HPA tissue IHC; general IHC practice). |
| Uniform color covers nuclei, stroma and cell-free regions. | Diffuse staining obscures the reported granular cytoplasmic pattern (HPA tissue IHC). Consider nonspecific detection or residual endogenous activity, depending on the chromogen system; inspect a no-primary control and the background outside cells (general IHC practice). |
| No detectable signal in adrenal glandular cells despite intact tissue morphology. | HPA reports High staining in these cells, so absence of signal calls for a technical check (HPA tissue IHC). It does not by itself prove loss of MT-CO2; verify the antibody, retrieval and detection setup against the assay controls (general IHC practice). |
💡Expected MT-CO2 appearanceCall a result positive when cells show granular cytoplasmic staining, including strong signal in HPA High populations such as adrenal glandular cells (HPA tissue IHC); predominantly nuclear or uniform cell-free color is suspect (UniProt P00403 topology; general IHC practice).
| Subcellular location and topology | MT-CO2 spans the inner mitochondrial membrane twice; its long C-terminal region faces the intermembrane space (UniProt P00403 topology). A section shows this as a cytoplasmic mitochondrial pattern, without resolving membrane sides (HPA tissue IHC; general IHC practice). |
| Tissue and cell context | HPA describes ubiquitous granular cytoplasmic expression, with High staining in several listed populations and Low staining in adipocytes (HPA tissue IHC). Use those relative levels; the payload supplies no truly negative tissue (HPA tissue IHC). |
| IHC evidence strength | The tissue profile has Enhanced reliability through staining and RNA consistency (HPA tissue IHC). Three listed antibodies have Enhanced IHC status (HPA antibodies). These designations support pattern interpretation, not an assay-specific cutoff (general IHC practice). |
| Processing and isoforms | UniProt lists one 227 aa chain, no annotated isoforms, signal peptide or propeptide, and no glycosylation sites (UniProt P00403). These records provide no basis for predicting a distinct processed or glycosylated staining compartment. |
| IF/ICC interpretation | For the separate IF/ICC guide: expect a mitochondrial distribution from UniProt topology, but HPA supplies only a broad 'Membrane' summary, no main location, no ICC/IF images and no ICC status for the listed antibodies (UniProt P00403; HPA subcellular; HPA antibodies). |
| Situation | Likely cause | Next action |
|---|---|---|
| A known HPA-high population is blank. | Target-specific fixation effects are not established by the supplied assay evidence. Verify with a matched IHC source before attributing a result to fixation. | Confirm tissue identity, primary antibody, retrieval settings and chromogen activity with appropriate run controls before interpreting biological absence (general IHC practice). |
| Signal is nuclear or forms a sharp cell-surface rim. | That distribution conflicts with the inner mitochondrial membrane location and granular cytoplasmic tissue profile (UniProt P00403 topology; HPA tissue IHC). | Check the no-primary control, inspect cellular morphology and repeat with an independently IHC-validated antibody if available (general IHC practice; HPA antibodies). |
| Color persists in cell-free regions or a no-primary control. | Background can arise from the detection system or residual endogenous enzyme activity when enzyme-based detection is used (general IHC practice). | Check the detection reagents and blocking controls, then adjust the relevant background-control step for the chosen chromogen system (general IHC practice). |
| Adipocytes stain more strongly than adjacent expected-positive cells. | This reverses HPA's reported Low adipocyte level relative to its listed High cell populations (HPA tissue IHC). | Compare the signal's granular cytoplasmic distribution and review no-primary and independent-antibody controls before treating the contrast as biological (HPA tissue IHC; general IHC practice). |
| All cells show dense color that hides intracellular granules. | Excess assay signal or diffuse background may conceal the expected granular pattern; HPA does not specify a dilution for this run (HPA tissue IHC; general IHC practice). | Titrate primary antibody and detection time using the same controls, then score only interpretable cellular staining (general IHC practice). |
| An IF image lacks a convincing mitochondrial pattern. | HPA offers no ICC/IF images or ICC validation status for the listed antibodies, so its tissue IHC evidence cannot validate that image (HPA subcellular; HPA antibodies). | Assess the IF result with its own localization and specificity controls; use UniProt's inner membrane annotation as the location expectation (general IF practice; UniProt P00403 topology). |
Experiment evidence
IHC & IF images showing MT-CO2 staining
A03631-1 · IHCIHC analysis of MT-CO2 using anti-MT-CO2 antibody (A03631-1). MT-CO2 was detected in a paraffin-embedded section of human colorectal cancer
A03631-1 · IHCIHC analysis of MT-CO2 using anti-MT-CO2 antibody (A03631-1). MT-CO2 was detected in a paraffin-embedded section of human glioma tissue. Hea
M03631-2 · IHCHuman kidney was stained with Anti-MTCO2 rabbit antibody
M03631-2 · IHCHuman liver was stained with Anti-MTCO2 rabbit antibody
M03631 · IHCImmunohistochemical analysis of paraffin-embedded human liver, using MTCO2 Antibody.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000198712-MT-CO2/tissue/cerebral+cortex#imid_15362222
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000198712-MT-CO2/tissue/colon#imid_15362156
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000198712-MT-CO2/tissue/liver#imid_15362157
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000198712-MT-CO2/tissue/kidney#imid_15362158
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for MT-CO2 IHC & IF
🧪Run bone marrow first; hematopoietic cells should show cytoplasmic mitochondrial staining (HPA: High in hematopoietic cells; UniProt P00403: mitochondrial inner membrane). HPA detects MT-CO2 in all 45 scored tissues, so there is no supported negative tissue; use no-primary and isotype controls, and expect any internally unstained cells to lack granular cytoplasmic signal without treating a named cell type as a validated negative (HPA: detected in all 45 scored tissues).
Positive control tissue: Adrenal gland (Glandular cells, HPA High)
Negative control tissue: None in HPA: MT-CO2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for MT-CO2; 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 slide and a rabbit IgG isotype control matched to the primary antibody’s clonality and concentration (selected-SKU caption: rabbit anti-MT-CO2 primary). A confirmed MT-CO2 knockout sample would provide a biological negative; quench endogenous peroxidase before DAB detection because hematopoietic cells can contain peroxidase activity (HPA: High in bone marrow hematopoietic cells; standard IHC practice).
⚠️Feasibility: The selected-SKU paraffin-section caption reports heat retrieval in EDTA at pH 8.0 and detection at 2 μg/ml, but its fixative is unreported (selected-SKU tissue-IHC caption). No target-specific fixation window or fixation effect is reported in the supplied evidence, and the caption does not establish that retrieval is required in every preparation; there is also insufficient matched evidence to say frozen sections or IF are easier (selected-SKU tissue-IHC caption; HPA subcellular record: no ICC-IF image cell lines). In bone marrow, endogenous peroxidase in hematopoietic cells can mimic chromogenic signal unless adequately quenched (HPA: High in bone marrow hematopoietic cells; standard IHC practice).
HPA tissue IHC evidence for MT-CO2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Appendix | Endocrine cells | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Breast | Glandular cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: MT-CO2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced MT-CO2 IHC Tips
Troubleshoot MT-CO2 staining in paraffin section IHC by checking retrieval, controls, mitochondrial localisation and scoring before interpreting signal differences.
Which retrieval conditions should I try first for weak MT-CO2 staining?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 (datasheet A03631-1). The catalog antibody stained a paraffin-embedded human colorectal cancer section after this retrieval, followed by 2 μg/ml primary antibody overnight at 4°C (datasheet A03631-1). If staining is weak, vary heating duration on matched sections while keeping EDTA and detection conditions constant (standard IHC practice). Include a control section with expected granular cytoplasmic staining so a failed run is distinguishable from a weak study sample (HPA: ubiquitous granular cytoplasmic expression; standard IHC practice). Record retrieval conditions for every comparison because changes in exposure can change apparent staining intensity (standard IHC practice).
How should I assess whether fixation is causing weak MT-CO2 IHC?
Target-specific sensitivity to fixation is unknown: the selected paraffin-section caption does not report a fixative (datasheet A03631-1). Do not assign a fixation effect from the tissue staining profile or membrane topology; neither measures fixation sensitivity (HPA: tissue IHC profile; UniProt P00403 topology). Compare sections with documented processing histories under the same EDTA pH 8.0 retrieval and detection conditions (datasheet A03631-1; standard IHC practice). A control section from the same processing batch helps identify a batch-wide staining failure, while matched morphology helps reveal processing damage (standard IHC practice). Report the fixative and fixation time when available rather than describing this caption as evidence for a particular fixation method (datasheet A03631-1; standard IHC practice).
What staining pattern is plausible for MT-CO2 in paraffin sections?
Expect granular cytoplasmic staining that is compatible with mitochondria, where MT-CO2 resides in the inner membrane (HPA: ubiquitous granular cytoplasmic expression; UniProt P00403 localisation). The protein has 2 transmembrane segments, at residues 15–45 and 60–87, so section staining may reflect organelle distribution rather than a cell-surface outline (UniProt P00403 topology). Assess signal within intact cell boundaries and compare nearby cells using the same staining run (standard IHC practice). Diffuse nuclear staining does not match the annotated compartment and needs independent validation before being scored as MT-CO2 (UniProt P00403 localisation; standard IHC practice). Granularity alone is insufficient to establish antibody specificity; use appropriate positive and reagent controls (standard IHC practice).
Could epitope orientation or isoforms explain variable MT-CO2 staining?
No isoforms are annotated for the 227-residue MT-CO2 chain, so an isoform switch is not an evidence-based explanation here (UniProt P00403 isoforms and processing). Its 2 membrane spans separate an intermembrane-space segment at residues 1–14, a matrix loop at 46–59, and an intermembrane-space region at 88–227 (UniProt P00403 topology). The supplied antibody caption does not map its epitope, so access to a particular side of the inner membrane remains unknown (datasheet A03631-1; UniProt P00403 topology). Optimize the documented EDTA pH 8.0 retrieval before attributing weak staining to epitope masking (datasheet A03631-1; standard IHC practice). No glycosylation sites or modified residues are annotated, which does not establish antibody epitope behavior in sections (UniProt P00403 annotations).
How should I adapt the MT-CO2 question to multiplex IF?
Treat IF as a separate assay requiring its own validation; the supplied antibody example documents chromogenic paraffin-section IHC with DAB (datasheet A03631-1). Multiplex MT-CO2 with a marker for the cell population being evaluated, and check that granular signal remains inside marker-defined cells (HPA: granular cytoplasmic expression; standard IF practice). Choose fluorophores and imaging channels after measuring tissue autofluorescence, using an unstained section and single-label controls to assess bleed-through (standard IF practice). MT-CO2 spans the mitochondrial inner membrane, but the antibody epitope is unmapped; establish permeabilisation empirically before claiming access to either membrane side (UniProt P00403 topology; datasheet A03631-1). Keep exposure settings consistent when comparing samples (standard IF practice).
How can I reduce background without losing mitochondrial signal?
First distinguish granular cellular staining from diffuse deposit or edge staining on a negative reagent control (HPA: granular cytoplasmic expression; standard IHC practice). The documented paraffin-section example used 10% goat serum block, 2 μg/ml primary antibody overnight at 4°C, and an anti-rabbit secondary for 30 minutes at 37°C (datasheet A03631-1). For DAB IHC, include an endogenous peroxidase block and check the secondary-only control before changing primary concentration (standard IHC practice). If background persists, titrate primary antibody around the documented condition and compare washes on matched sections (datasheet A03631-1; standard IHC practice). Judge improvement against retained granular cytoplasmic signal, not a uniformly paler slide (HPA: tissue IHC profile; standard IHC practice).
What should I score when comparing MT-CO2 IHC between samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and analysis regions before scoring, excluding folds, damaged edges and necrotic areas (standard IHC practice). An H-score combines the percentage of cells at each intensity grade into a 0–300 score; report the scoring rules and the percentage of positive cells alongside it (standard IHC practice). Score granular cytoplasmic signal within intact cells because that pattern fits the reported profile and mitochondrial location (HPA: granular cytoplasmic expression; UniProt P00403 localisation). Normalize counts or stained area to the number of evaluable cells or tissue area, and keep retrieval, DAB development and imaging settings consistent across comparisons (standard IHC practice). Stratify distinct cell populations when their staining differs rather than averaging them into one field score (standard IHC practice).
When is MT-CO2 staining convincing, and when is it artefact?
Convincing MT-CO2 staining is granular and cytoplasmic within intact cells, consistent with its mitochondrial inner-membrane location (HPA: tissue IHC profile; UniProt P00403 localisation). High staining occurs in several listed populations, including adrenal glandular cells and neuronal cells, while adipocytes are listed as low; interpret signal in the identified cell population rather than by tissue name alone (HPA: listed tissue IHC levels). Nuclear-only signal conflicts with the annotated compartment and warrants a specificity check (UniProt P00403 localisation; standard IHC practice). Exclude edge staining and necrotic debris, and check endogenous peroxidase and secondary-only controls before accepting unexpected DAB signal (standard IHC practice). A positive control processed with the study sections helps distinguish a biological difference from a staining-run failure (standard IHC practice).
Boster reagents
Best MT-CO2 / Cytochrome c oxidase subunit 2 IHC Antibodies
Three anti-MT-CO2 antibodies have IHC images from human tissue; one also has mouse and rat tissue images (catalog IHC captions). Two list IF as an application, without IF images (catalog applications and image listings).
Real IHC data
Anti-MT-CO2 Antibody ®
Cat # A03631-1
Real IHC data
Anti-MTCO2 Rabbit Monoclonal Antibody
Cat # M03631-2
Real IHC data
Anti-MTCO2 Rabbit Monoclonal Antibody
Cat # M03631
A03631-1 has IHC images from human colorectal cancer and glioma, mouse brain, and rat brain (A03631-1 IHC captions). M03631-2 has IHC images from human kidney and liver (M03631-2 IHC captions); M03631 has an IHC image from paraffin-embedded human liver (M03631 IHC caption).
Which to pick: For human tissue IHC, M03631 has a paraffin-section image, while M03631-2 has human kidney and liver images whose processing is unspecified (respective IHC captions); the fixative is unreported for both (respective IHC captions). For IF/ICC, M03631 lists both applications, whereas M03631-2 lists IF only (catalog applications); neither has an IF image in this payload (catalog image listings). For cross-species IHC, choose A03631-1: its IHC captions show paraffin sections from human, mouse, and rat, and its listed reactivity covers all three species (A03631-1 IHC captions; catalog reactivity); the fixative is unreported (A03631-1 IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P00403 (COX2_HUMAN, Cytochrome c oxidase subunit 2).
- Human Protein Atlas. MT-CO2 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. MT-CO2 subcellular location (ICC-IF): Membrane.
- Human Protein Atlas. MT-CO2 antibody validation summary (3 antibodies).
- Mitochondrial-cytochrome c oxidase II promotes glutaminolysis to sustain tumor cell survival upon glucose deprivation. Nature communications 2025 — PMC11695821.
- Expression of mitochondrial regulators PGC1α and TFAM as putative markers of subtype and chemoresistance in epithelial ovarian carcinoma. PloS one 2014 — PMC4170973.
- Non-canonical dihydrolipoyl transacetylase promotes chemotherapy resistance via mitochondrial tetrahydrofolate signaling. Nature communications 2025 — PMC12508156.
- PubMed PMID:7219534 — UniProt-cited evidence.
- PubMed PMID:2550900 — UniProt-cited evidence.
- PubMed PMID:226894 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for MT-CO2 (Cytochrome c oxidase subunit 2). Expected localisation Granular cytoplasm observed (HPA tissue IHC); inner mitochondrial membrane expected (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A03631-1). Validated IHC antibody: A03631-1 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colorectal cancer tissue; fixative not specified (datasheet A03631-1); 2. Fixation: Image fixative and duration unreported (datasheet A03631-1); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet A03631-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A03631-1); 8. Primary antibody: Rabbit anti-MT-CO2, 2-5 μg/ml (datasheet A03631-1); 9. Primary incubation: Overnight at 4 °C (datasheet A03631-1). Watch for: Fixation: Keep paraffin-section fixation consistent across samples (standard IHC practice; not target-specific); Caveat: Ubiquitous staining limits cell-type discrimination (HPA tissue IHC); Isoform / epitope: No annotated isoforms or cleavage; epitope position matters (UniProt); Regulation: No expression regulator annotated (UniProt). Evidence: UniProt P00403, HPA tissue IHC · Enhanced, HPA ICC-IF · Membrane, Datasheet A03631-1, PMC11695821, PMC4170973. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/MT-CO2/immunohistochemistry-ihc-guide.