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METAP2 / Methionine aminopeptidase 2 · IHC design guide
Design Immunohistochemistry for METAP2
Plan METAP2 chromogenic IHC in paraffin sections using its widespread cytoplasmic tissue pattern as a reference (HPA tissue IHC). Start with the catalog antibody’s IHC dilution of 2–5 μg/ml (datasheet A03648-2) and compare sections fixed consistently (standard IHC practice).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
METAP2 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 | Cytoplasmic staining across tissues (HPA tissue IHC) | |
| Staining pattern | Widespread cytoplasmic staining across tissues (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A03648-2) | |
| Positive control | Bone marrow+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 fixation consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Widespread staining limits negative tissue controls (HPA tissue IHC) | |
| Regulation | Low tissue specificity; no regulator reported (HPA tissue IHC; UniProt) | |
| Isoform / epitope | 3 isoforms; epitope effects are unresolved (UniProt) |
Section 1
Recommended METAP2 IHC & IF Protocols
The catalog antibody uses heat-mediated EDTA retrieval at pH 8.0 (datasheet A03648-2). The published METAP2 IHC protocols below provide sample-specific methods (PMC3324555; PMC11082409; PMC8137584; PMC7484650).
| Sample | Paraffin-embedded human colorectal adenocarcinoma tissue; fixative not specified (datasheet A03648-2) |
| Fixation | Image fixative and duration unreported (datasheet A03648-2); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A03648-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A03648-2) |
| Primary antibody | Rabbit anti-METAP2, 2-5 μg/ml (datasheet A03648-2) |
| Primary incubation | Overnight at 4 °C (datasheet A03648-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A03648-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | METAP2-positive staining in hematopoietic cells of bone marrow (HPA tissue IHC: High). HPA tissue profile: Ubiquitous cytoplasmic expression in all tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 for the catalog antibody (datasheet A03648-2). Published citrate retrieval conditions apply to their respective antibodies (PMC3324555; PMC7484650).
Section 2
What Is the Expected METAP2 Staining Pattern?
METAP2 should show widespread cytoplasmic staining in paraffin tissue sections, with particularly strong staining in the cell populations listed below (HPA: ubiquitous cytoplasmic tissue IHC; Enhanced reliability). UniProt places METAP2 in the cytoplasm and reports no transmembrane segment (UniProt P50579). HPA calls the tissue IHC reliability Enhanced while describing only medium consistency between antibody staining and RNA expression; interpret intensity differences with that qualification (HPA: tissue IHC reliability).
| Cytoplasmic staining across several tissues, strongest in selected cell populations. | This fits HPA's ubiquitous cytoplasmic pattern. High staining is reported in bone marrow hematopoietic cells, kidney glomerular cells and lung alveolar type I cells (HPA: tissue IHC). Compare cells within each tissue; widespread expression does not imply equal intensity everywhere (HPA: tissue IHC levels). |
| Predominantly nuclear staining, or a crisp membrane rim without cytoplasmic staining. | These are unexpected as the principal chromogenic tissue IHC pattern (HPA: ubiquitous cytoplasmic tissue IHC; UniProt P50579: cytoplasm). Check whether the signal follows tissue edges, pigment or detection background before assigning METAP2. A membrane location is reported separately in ICC-IF and does not establish a membrane-only tissue IHC pattern (HPA: subcellular ICC-IF). |
| Strong staining confined to a cell population reported as low, with weak staining in nearby expected-positive cells. | Consider cross-reactivity or cell-specific detection background before calling this a METAP2-enriched population. HPA reports low staining in cardiomyocytes, skeletal myocytes, smooth muscle cells, fibroblasts and adipocytes; low is not absent (HPA: tissue IHC). |
| Uniform haze over cells and extracellular areas, obscuring cell boundaries. | Treat this as background until cellular staining can be separated from it. Uneven blocking, residual chromogen or endogenous detection activity are general IHC possibilities, not METAP2-specific findings (standard IHC practice). Compare a no-primary control and the expected cytoplasmic cell pattern (HPA: tissue IHC). |
| No signal in a section containing an HPA high-staining population. | An absent result in bone marrow hematopoietic cells or tonsil germinal center cells conflicts with the reported tissue pattern (HPA: High in those cells). First verify section quality, retrieval, antibody application and detection with suitable controls (standard IHC practice); a blank slide alone cannot establish true absence of METAP2. |
💡Expected METAP2 appearanceCall the result positive when staining is cellular and chiefly cytoplasmic, with conspicuous signal in an HPA high-staining population such as tonsil germinal center cells (HPA: ubiquitous cytoplasmic IHC; High in tonsil germinal center cells). A nuclear-only pattern, extracellular haze or chromogen in a no-primary control argues against a specific positive call (standard IHC interpretation).
| Tissue and cell choice | HPA reports High staining in bone marrow hematopoietic cells, glomerular cells, alveolar type I cells, lymph node and tonsil germinal center cells, seminal vesicle glandular cells, and late spermatids (HPA: tissue IHC). It reports Medium in adrenal glandular cells and Low in several stromal, muscle and adipose populations; these levels guide comparison rather than define negative tissue (HPA: tissue IHC). |
| Location evidence and antibody validation | The tissue reference pattern is cytoplasmic, and both listed antibodies have Enhanced IHC status (HPA: tissue IHC; HPA019095 and CAB013025). Enhanced reflects independent-antibody or orthogonal support, while HPA still reports medium staining–RNA consistency; neither statement validates every unexpected compartment or cell type (HPA: reliability description and antibody validation). |
| Isoforms and epitope coverage | UniProt lists three METAP2 isoforms and a processed chain spanning residues 2–478 (UniProt P50579). The supplied records give no epitope location or isoform-specific IHC result, so a difference between antibodies cannot be assigned to a particular isoform from this evidence. |
| Detection chemistry | In chromogenic IHC, endogenous enzyme activity or tissue pigment can resemble antibody-derived colour (standard IHC practice). A no-primary control and review of cellular localisation help distinguish these from the expected cytoplasmic signal (HPA: tissue IHC pattern). This is a general workflow consideration, not a reported METAP2 tissue property. |
| IF/ICC Q&A | Q: Should IF/ICC look identical to paraffin IHC? A: HPA reports cytosol as supported and plasma membrane as approved in ICC-IF, with images from A-431, U-251MG and U2OS (HPA: subcellular ICC-IF). Interpret those cellular images on their own terms; the tissue IHC reference remains cytoplasmic (HPA: tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected-positive tissue is blank. | The run may have lost antigen detection or the selected section may lack the relevant cells; absence in HPA high-staining cells conflicts with the reference pattern (HPA: tissue IHC). | Confirm the expected cell population is present. Review retrieval, primary-antibody application and detection controls as general IHC checks; assess a known-positive section in the same run (standard IHC practice). |
| Signal is faint everywhere, including in reported high-staining cells. | Weak staining may reflect a general assay sensitivity problem; the supplied sources give no METAP2-specific fixation effect or required antibody dilution (HPA: tissue IHC; supplied source scope). | Check the catalog antibody's own IHC-P instructions, reagent performance and retrieval settings before changing interpretation. Compare high and low HPA populations under the same staining conditions (standard IHC practice; HPA: tissue IHC levels). |
| Strong nuclear-only or membrane-only chromogen dominates. | The principal tissue IHC pattern is cytoplasmic (HPA: tissue IHC; UniProt P50579). HPA's plasma-membrane observation comes from ICC-IF, so it does not by itself explain membrane-only paraffin IHC (HPA: subcellular ICC-IF). | Inspect cell outlines and counterstain, compare a no-primary control, and repeat with the IHC-validated antibody or an independently validated antibody if available (standard IHC practice; HPA: Enhanced IHC antibodies). |
| Diffuse colour covers cells and spaces between them. | Nonspecific reagent binding, endogenous detection activity or pigment can produce background in chromogenic IHC (standard IHC practice). Such haze cannot be scored as METAP2's cellular cytoplasmic pattern (HPA: tissue IHC). | Use a no-primary control, check blocking and detection steps, and score only signal that can be assigned to cells with the expected localisation (standard IHC practice; HPA: tissue IHC). |
| A low-staining population appears stronger than an HPA high-staining population. | HPA levels describe observed patterns, not absolute expression cutoffs; a reversal may reflect section composition, scoring or nonspecific staining (HPA: tissue IHC levels; standard IHC interpretation). | Identify the cell types before comparing intensity, then check controls and staining across another suitable section. Do not treat HPA Low populations as negative controls (HPA: tissue IHC). |
| Two IHC antibodies give different cell patterns. | Both listed antibodies have Enhanced IHC status, but the supplied evidence does not identify their epitopes or isoform coverage (HPA: HPA019095 and CAB013025; UniProt P50579: three isoforms). | Compare the same tissue and cell populations with matched detection controls; report the disagreement and avoid attributing it to an isoform or processing site without further evidence (standard IHC practice). |
Experiment evidence
IHC & IF images showing METAP2 staining
A03648-2 · IHCIHC analysis of METAP2 using anti-METAP2 antibody (A03648-2). METAP2 was detected in a paraffin-embedded section of human colorectal adenoca
A03648-2 · IHCIHC analysis of METAP2 using anti-METAP2 antibody (A03648-2). METAP2 was detected in a paraffin-embedded section of human brain tissue. Heat
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000111142-METAP2/tissue/cerebral+cortex#imid_5876248
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000111142-METAP2/tissue/colon#imid_5876174
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000111142-METAP2/tissue/liver#imid_5876167
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000111142-METAP2/tissue/kidney#imid_5876160
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA019095; green = METAP2, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA019095; green = METAP2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for METAP2 IHC & IF
🧪Run bone marrow first and look for staining in hematopoietic cells (HPA: High in hematopoietic cells). HPA detects METAP2 in all 45 scored tissues, so there is no validated negative tissue or internal negative cell population; any apparently unstained cells on the positive slide should show only background, with the no-primary and isotype controls defining that background (HPA: no negative rows).
Positive control tissue: Bone marrow (Hematopoietic cells, HPA High)
Negative control tissue: None in HPA: METAP2 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 ICC-IF images show METAP2 in A-431, U-251MG, U2OS, with annotated localisation: Plasma membrane (approved), Cytosol (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only section, a concentration-matched rabbit IgG isotype section, and a matched METAP2 knockout or depleted specimen if available (caption: rabbit primary antibody; standard IHC controls). Quench endogenous peroxidase in bone marrow before HRP–DAB detection because hematopoietic cells can contribute peroxidase background (HPA: bone marrow hematopoietic cells; caption: HRP–DAB detection; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A03648-2 paraffin-section caption does not state the fixative (caption: fixative not stated). The documented IHC procedure uses heat retrieval in EDTA at pH 8.0, but the evidence does not establish that retrieval is required; frozen-section performance is unreported, while HPA provides ICC–IF images for A-431, U-251MG and U2OS rather than a tissue IF protocol (caption: EDTA retrieval; HPA: ICC–IF image cell lines). In bone marrow, endogenous peroxidase can complicate HRP–DAB interpretation (HPA: bone marrow hematopoietic cells; caption: HRP–DAB detection; standard IHC practice).
HPA tissue IHC evidence for METAP2
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 |
|---|---|---|---|---|
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Kidney | Cells in glomeruli | High | Protein (IHC) | HPA → |
| Lung | Alveolar cells type I | High | Protein (IHC) | HPA → |
| Lymph node | Germinal center cells | High | Protein (IHC) | HPA → |
| Seminal vesicle | Glandular cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: METAP2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced METAP2 IHC Tips
Troubleshoot METAP2 staining in paraffin sections using the catalog antibody’s tissue result, cellular localisation, and appropriate IHC controls.
How should I adjust retrieval when METAP2 staining is weak in paraffin sections?
Start with heat mediated retrieval in EDTA at pH 8.0 (datasheet A03648-2). The catalog antibody detected METAP2 in a paraffin section after that retrieval, followed by 10% goat serum blocking and 2 μg/ml primary antibody overnight at 4°C (datasheet A03648-2). If staining is weak, check heating consistency, section adhesion, and reagent performance before testing another buffer as a fallback (standard IHC practice). Compare any fallback on adjacent sections with the same detection and development conditions, and retain the condition that improves cellular signal without increasing diffuse background (standard IHC practice).
Could fixation explain weak or uneven METAP2 staining?
Target specific fixation sensitivity is unknown: the selected paraffin section caption does not state a fixative (datasheet A03648-2). Record each specimen’s fixative and fixation duration, then compare similarly processed sections before attributing a staining difference to METAP2 abundance (standard IHC practice). Keep section thickness, EDTA retrieval at pH 8.0, antibody concentration, and chromogen development consistent during that comparison (datasheet A03648-2; standard IHC practice). Uneven staining near folds or section edges warrants a processing and reagent coverage check, but neither tissue staining patterns nor METAP2 topology establishes a target specific fixation effect (standard IHC practice; HPA: tissue IHC; UniProt P50579 topology).
Which staining pattern should I expect, and how should I assess membrane staining?
Assess cytoplasmic staining first: METAP2 is annotated in the cytoplasm, with about 30% of expressed protein associated with polysomes (UniProt P50579 subcellular). HPA reports ubiquitous cytoplasmic tissue staining and cytosol plus an approved plasma membrane location in cellular imaging, so a membrane outline alone needs corroboration (HPA: tissue IHC; HPA: subcellular). The protein has no annotated transmembrane segment, which does not by itself rule out membrane association (UniProt P50579 topology; HPA: subcellular). Compare membrane and cytoplasmic signals across intact cells, a primary antibody omission control, and a second detection condition before assigning a compartment specific result (standard IHC practice).
How can I assess whether epitope variation affects METAP2 staining?
METAP2 has 3 annotated isoforms, while the supplied tissue caption does not identify the catalog antibody’s epitope or isoform coverage (UniProt P50579 isoforms; datasheet A03648-2). Residues 60 and 63 have annotated glycosylation sites and alternate phosphoserine annotations, but their effect on this antibody’s IHC staining is unreported (UniProt P50579 modifications; datasheet A03648-2). Check the antibody’s epitope documentation before interpreting a negative section as absence of every isoform (standard IHC practice). If specificity remains uncertain, compare staining with an independently mapped epitope or a validated loss of METAP2 control using matched processing and scoring (standard IHC practice).
How should I assess METAP2 in a multiplex IF experiment?
For an IF experiment, pair METAP2 with a marker identifying the expected cell type, such as hematopoietic cells in bone marrow, and inspect cellular overlap rather than relying on field brightness (HPA: High in bone marrow hematopoietic cells; standard IF practice). Choose a spectrally separated fluorophore, preferably in a channel with low measured tissue autofluorescence, and include single stain and unstained controls for bleed through and autofluorescence (standard IF practice). METAP2 is cytoplasmic and lacks a transmembrane segment; choose permeabilisation to expose the relevant intracellular epitope, then validate that choice for the IF antibody (UniProt P50579 subcellular and topology; standard IF practice). Assess cytosolic and membrane signal separately because HPA reports both locations in cellular imaging (HPA: subcellular).
What should I check when DAB background obscures METAP2 staining?
Compare the test section with primary antibody omission and detection controls to locate background arising from secondary reagent, endogenous peroxidase, or chromogen development (standard IHC practice). The reported tissue workflow used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, peroxidase conjugated secondary antibody, and DAB (datasheet A03648-2). Apply a peroxidase block and keep development conditions consistent across sections; these are general chromogenic IHC controls, not demonstrated METAP2 requirements (standard IHC practice). If diffuse staining persists, check washes, antibody concentration, and damaged tissue while preserving interpretable cytoplasmic signal (standard IHC practice; HPA: ubiquitous cytoplasmic expression).
How should I quantify METAP2 staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and viable tissue region before scoring, because HPA reports ubiquitous cytoplasmic expression with differing staining levels among cell populations (HPA: tissue IHC). For cellular intensity, record the percentage of cells at each ordinal intensity and calculate an H-score from 0–300; also report percentage positive cells when intensity estimates are unreliable (standard IHC practice). For a spatial question, report positive cell density per mm² of viable annotated tissue and retain the total evaluated cell count (standard IHC practice). Normalise comparisons to the same cell type, tissue area or cell denominator, imaging settings, and chromogen development, with thresholds fixed before comparing groups (standard IHC practice).
How do I distinguish convincing METAP2 staining from artefact?
A convincing result should show reproducible cellular staining with a prominent cytoplasmic component, consistent with UniProt localisation and HPA tissue staining (UniProt P50579 subcellular; HPA: tissue IHC). Membrane staining can be plausible because HPA also reports a plasma membrane location, but an isolated rim or signal in an unexpected cell population merits independent confirmation (HPA: subcellular; standard IHC practice). Exclude folds, cut edges, necrotic regions, and deposits before scoring, and check whether a primary antibody omission control retains DAB signal from endogenous enzyme activity (standard IHC practice). Interpret weak staining against matched controls and cell composition; HPA reports medium consistency between antibody staining and RNA expression (HPA: tissue IHC).
Boster reagents
Best METAP2 / Methionine aminopeptidase 2 IHC Antibodies
Anti-METAP2 options include pictured human paraffin-section IHC (A03648-2 image captions) and a listed IF/ICC application without a supplied image (M03648-1 catalog).
Real IHC data
Anti-METAP2 Antibody ®
Cat # A03648-2
A03648-2 has IHC images from human colorectal adenocarcinoma, brain, and tonsil paraffin sections (A03648-2 image captions). M03648-1 lists IHC and IF/ICC applications and human, mouse, and rat reactivity, but supplies no IHC or IF image (M03648-1 catalog).
Which to pick: For tissue IHC, choose A03648-2: its human paraffin-section captions document EDTA retrieval at pH 8.0 and antibody at 2 μg/ml; the fixative is unreported (A03648-2 image captions). For IF/ICC, M03648-1 is the rabbit monoclonal option, clone 20M17, with IF/ICC listed but no supplied IF image (M03648-1 catalog). For cross-species planning, A03648-2 lists human, mouse, rat, and monkey reactivity, while M03648-1 lists human, mouse, and rat; the pictured IHC results for A03648-2 are human (catalog reactivity; A03648-2 image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P50579 (MAP2_HUMAN, Methionine aminopeptidase 2).
- Human Protein Atlas. METAP2 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. METAP2 subcellular location (ICC-IF): Localized to the plasma membrane and cytosol..
- Human Protein Atlas. METAP2 antibody validation summary (2 antibodies).
- Early treatment with fumagillin, an inhibitor of methionine aminopeptidase-2, prevents Pulmonary Hypertension in monocrotaline-injured rats. PloS one 2012 — PMC3324555.
- The Proteome Landscape of Human Placentas for Monochorionic Twins with Selective Intrauterine Growth Restriction. Genomics, proteomics & bioinformatics 2023 — PMC11082409.
- In Vivo Imaging of Methionine Aminopeptidase II for Prostate Cancer Risk Stratification. Cancer research 2021 — PMC8137584.
- CHD1L promotes EOC cell invasiveness and metastasis via the regulation of METAP2. International journal of medical sciences 2020 — PMC7484650.
- PubMed PMID:7644482 — UniProt-cited evidence.
- PubMed PMID:7873610 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for METAP2 (Methionine aminopeptidase 2). Expected localisation Cytoplasmic staining across tissues (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A03648-2). Validated IHC antibody: A03648-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Bone marrow (Hematopoietic 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 adenocarcinoma tissue; fixative not specified (datasheet A03648-2); 2. Fixation: Image fixative and duration unreported (datasheet A03648-2); 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: EDTA pH 8.0 (datasheet A03648-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A03648-2); 8. Primary antibody: Rabbit anti-METAP2, 2-5 μg/ml (datasheet A03648-2); 9. Primary incubation: Overnight at 4 °C (datasheet A03648-2). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Widespread staining limits negative tissue controls (HPA tissue IHC); Isoform / epitope: 3 isoforms; epitope effects are unresolved (UniProt); Regulation: Low tissue specificity; no regulator reported (HPA tissue IHC; UniProt). Evidence: UniProt P50579, HPA tissue IHC · Enhanced, HPA ICC-IF · plasma membrane and cytosol., Datasheet A03648-2, PMC3324555, PMC11082409. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/METAP2/immunohistochemistry-ihc-guide.