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PTPN11 / Tyrosine-protein phosphatase non-receptor type 11 · IHC design guide
Design Immunohistochemistry for PTPN11
Plan PTPN11 chromogenic IHC in paraffin sections using its general cytoplasmic tissue pattern (HPA tissue IHC). Colon glandular cells show high staining, while skeletal myocytes are not detected; use these observations to plan controls and interpret cell-specific staining (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PTPN11 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 in tissue IHC (HPA tissue IHC); nucleus annotated (UniProt) | |
| Staining pattern | General cytoplasmic staining across tissue cell types (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet M00150-1) | |
| Positive control | Adipose tissue+4 more · see all | |
| Negative control | Skeletal muscle |
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 M00150-1); verify before use. | |
| Caveat | Skeletal myocytes lack staining despite reported muscle expression (HPA tissue IHC; UniProt) | |
| Regulation | Expression regulation unreported (UniProt) | |
| Isoform / epitope | 3 isoforms; map the antibody epitope across them (UniProt) |
Section 1
Recommended PTPN11 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is followed by published PTPN11 staining methods for human skin biopsies, testis biopsies, and hepatocellular carcinoma xenograft tissue (PMC4960761; PMC11035881; PMC10272960).
| Sample | Paraffin-embedded human colon tissue; fixative not specified (datasheet M00150-1) |
| Fixation | Image fixative and duration unreported (datasheet M00150-1); 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 M00150-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet M00150-1) |
| Primary antibody | Rabbit monoclonal (clone GBO-16) anti-PTPN11, 1:50 (datasheet M00150-1) |
| Primary incubation | Overnight at 4 °C (datasheet M00150-1) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet M00150-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | PTPN11-positive staining in adipocytes of adipose tissue (HPA tissue IHC: High). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA at pH 8.0 for the catalog antibody (datasheet: M00150-1); published skin and xenograft protocols used citrate at pH 6.0 (PMC4960761; PMC10272960).
Section 2
What Is the Expected PTPN11 Staining Pattern?
PTPN11 is a non-transmembrane protein localized to the cytoplasm and nucleus (UniProt Q06124: subcellular location and topology). In paraffin-section IHC, expect predominantly cytoplasmic staining across multiple cell types (HPA tissue IHC: general cytoplasmic expression; low tissue specificity). High staining is reported in selected glandular, stromal, glial, lymphoid and adipose cells (HPA tissue IHC). The tissue IHC profile is Approved, with medium consistency between staining and RNA expression (HPA tissue IHC: reliability).
| Cytoplasmic signal in colon glandular cells, endometrial stromal cells or glial cells (HPA tissue IHC: High in these cells). | This matches the reported tissue pattern, especially when the signal follows cell boundaries and a control omitting the primary antibody stays clear (HPA tissue IHC; general IHC practice). Nuclear signal can coexist because UniProt also assigns PTPN11 to the nucleus (UniProt Q06124: subcellular location). |
| Signal is confined to cell membranes or extracellular spaces, with little intracellular staining (general IHC observation). | Treat this as a pattern mismatch: PTPN11 has no transmembrane segment, and HPA describes general cytoplasmic tissue staining (UniProt Q06124: topology; HPA tissue IHC). Check the tissue outline and staining controls before assigning the signal to PTPN11 (general IHC practice). |
| Strong staining appears in skeletal myocytes while the selected high-staining cells are faint (HPA tissue IHC: myocytes Not detected; selected cells High). | Question specificity or cell identification, then review controls for cross-reactivity or endogenous detection activity (general IHC practice). HPA's myocyte result is an observed IHC pattern, not proof that every skeletal-muscle specimen lacks PTPN11 (HPA tissue IHC: Not detected in myocytes). |
| A uniform haze covers cells and empty tissue spaces, obscuring compartment boundaries (general IHC observation). | Diffuse background prevents a reliable localization call; compare a control omitting the primary antibody and inspect blocking, washes and chromogen development (general IHC practice). It does not match HPA's general cytoplasmic pattern (HPA tissue IHC). |
| No signal appears in adipocytes or colon glandular cells chosen as positive controls (HPA tissue IHC: High in both). | An absent control signal makes a negative result elsewhere inconclusive (general IHC practice). Check section integrity, retrieval and detection with the same run before interpreting the study tissue (general IHC practice); HPA reports high staining, not a guarantee for every specimen (HPA tissue IHC). |
💡Expected PTPN11 appearanceCall a positive IHC result when intracellular, chiefly cytoplasmic staining is clear in a relevant cell population, with strong signal plausible in HPA High cells; isolated membrane or extracellular color is suspect (HPA tissue IHC: general cytoplasmic expression and High cell populations; UniProt Q06124: topology; general IHC practice).
| Cell type and tissue (HPA tissue IHC) | HPA reports High staining in adipocytes, appendix lymphoid tissue, brain glia, cerebellar granular-layer cells, colon and epididymis glandular cells, and endometrial stromal cells; adrenal glandular cells, cholangiocytes and smooth-muscle cells are Low (HPA tissue IHC). Compare like cell types when judging intensity (general IHC practice). |
| Skeletal-muscle interpretation (UniProt Q06124; HPA tissue IHC) | UniProt describes high overall expression in skeletal muscle, while HPA tissue IHC reports myocytes as Not detected (UniProt Q06124: tissue specificity; HPA tissue IHC: skeletal myocytes). Keep the evidence types distinct; neither result alone validates a particular myocyte stain. |
| Topology and processing (UniProt Q06124) | PTPN11 lacks a transmembrane segment and a signal sequence; UniProt lists no propeptide (UniProt Q06124: topology and processing). These annotations support an intracellular interpretation but do not identify the antibody epitope or establish retrieval needs. |
| Isoforms and antibody evidence (UniProt Q06124; HPA antibodies) | UniProt lists three isoforms; the supplied record does not map the catalog antibody's epitope to them (UniProt Q06124: isoforms; supplied antibody data). CAB005377 has Approved IHC and Supported ICC status; no Enhanced IHC designation is supplied (HPA antibodies: CAB005377). |
| IF/ICC Q: Should a nucleoli-rim signal be expected in IHC? (HPA subcellular) | HPA ICC-IF places PTPN11 mainly at the nucleoli rim, with additional nucleoplasm, cytosol and actin-filament localization (HPA subcellular). This supports interpreting an IF image; it does not replace HPA's general cytoplasmic tissue-IHC pattern (HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| A high-staining control tissue gives no visible signal (HPA tissue IHC: High cells). | Possible section, retrieval or detection failure; the observation alone cannot identify which step failed (general IHC practice). | Confirm that the expected cell type is present, then check retrieval and detection using a previously working control in the same run (general IHC practice). Interpret study negatives only after the control works (general IHC practice). |
| Color appears throughout the slide, including spaces without cells (general IHC observation). | Background from nonspecific binding, endogenous detection activity or excess chromogen can obscure localization (general IHC practice). | Compare a control omitting the primary antibody; review blocking, washes and development time before scoring cellular staining (general IHC practice). |
| Only membrane outlines or extracellular material stain (general IHC observation). | That distribution conflicts with non-transmembrane PTPN11 and HPA's cytoplasmic IHC profile (UniProt Q06124: topology; HPA tissue IHC). | Check morphology and a control omitting the primary antibody; reassess the signal with a high-staining cellular control (general IHC practice; HPA tissue IHC: High cells). |
| Skeletal myocytes stain strongly (HPA tissue IHC: myocytes Not detected). | The signal may reflect nonspecific staining or a specimen difference; HPA's observation alone cannot decide which (HPA tissue IHC; general IHC practice). | Verify cell identity, compare controls and report the discrepancy rather than treating skeletal-muscle expression as validation of the IHC pattern (general IHC practice; UniProt Q06124: tissue specificity). |
| Adrenal glandular cells or cholangiocytes look weak (HPA tissue IHC: Low in both). | Low staining is consistent with HPA's cell-specific observations and is not, by itself, evidence of a failed run (HPA tissue IHC). | Judge them against a High cell population stained in the same run before changing conditions (HPA tissue IHC: High and Low populations; general IHC practice). |
| A nuclear signal accompanies cytoplasmic staining (UniProt Q06124: cytoplasm and nucleus). | Nuclear localization is annotated, but the ICC-IF nucleoli-rim finding does not establish the dominant pattern in paraffin-section IHC (UniProt Q06124; HPA subcellular; HPA tissue IHC). | Score cytoplasmic and nuclear compartments separately; check controls before accepting a predominantly nuclear IHC result (general IHC practice; HPA tissue IHC: general cytoplasmic expression). |
Experiment evidence
IHC & IF images showing PTPN11 staining
M00150-1 · IHCIHC analysis of SHP2/PTPN11 using anti-SHP2/PTPN11 antibody (M00150-1). SHP2/PTPN11 was detected in a paraffin-embedded section of human col
M00150-1 · IHCIHC analysis of SHP2/PTPN11 using anti-SHP2/PTPN11 antibody (M00150-1). SHP2/PTPN11 was detected in a paraffin-embedded section of human col
M00150-2 · IHCIHC analysis of SHP2/PTPN11 using anti SHP2/PTPN11 antibody (M00150-2). SHP2/PTPN11 was detected in paraffin-embedded section of human colon
M00150-2 · IHCIHC analysis of SHP2/PTPN11 using anti SHP2/PTPN11 antibody (M00150-2). SHP2/PTPN11 was detected in paraffin-embedded section of human colon
M00150-2 · IFIF analysis of SHP2/PTPN11 using anti-SHP2/PTPN11 antibody (M00150-2). SHP2/PTPN11 was detected in immunocytochemical section of U251 cells.
PA1860 · IHCIHC analysis of SHP2/PTPN11 using anti-SHP2/PTPN11 antibody (PA1860). SHP2/PTPN11 was detected in a paraffin-embedded section of human lung
PA1860 · IFIF analysis of SHP2/PTPN11 using anti-SHP2/PTPN11 antibody (PA1860). SHP2/PTPN11 was detected in an immunocytochemical section of PC-3 cells
M00150 · IHCImmunohistochemical analysis of paraffin-embedded human heart, using SHP2 Antibody.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000179295-PTPN11/tissue/cerebral+cortex#imid_2058248
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000179295-PTPN11/tissue/colon#imid_2058174
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000179295-PTPN11/tissue/liver#imid_2058175
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000179295-PTPN11/tissue/kidney#imid_2058168
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB005377; green = PTPN11, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB005377; green = PTPN11, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PTPN11 IHC & IF
🧪Run adipose tissue first; adipocytes should stain (HPA: High in adipocytes). Run skeletal muscle as the tissue negative; myocytes are listed as not detected (HPA: Not detected in myocytes). On the positive slide, cells without specific staining provide a background reference, but their PTPN11-negative status is unverified (HPA: adipocyte row only).
Positive control tissue: Adipose tissue (Adipocytes, HPA High)
Negative control tissue: Skeletal muscle (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PTPN11 in A-431, U-251MG, U2OS, with annotated localisation: Nucleoli rim (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and a rabbit IgG isotype control matched to the primary antibody’s clonality and concentration, plus PTPN11 knockout material as a biological negative (caption: rabbit primary; standard IHC practice). Block endogenous peroxidase and assess background around adipocyte lipid vacuoles when interpreting DAB staining (caption: HRP/DAB detection; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected M00150-1 tissue-IHC caption does not state the fixative (caption: fixative unreported). The caption uses heat retrieval in EDTA at pH 8.0, but does not establish whether retrieval is required for every specimen (caption: EDTA pH 8.0). The supplied evidence does not establish that frozen sections or IF are easier; adipocytes’ thin cytoplasmic rim can make staining harder to score (HPA: High in adipocytes; standard histology practice).
HPA tissue IHC evidence for PTPN11
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium consistency between antibody staining and RNA expression data.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | High | Protein (IHC) | HPA → |
| Appendix | Lymphoid tissue | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Skeletal muscle | Myocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced PTPN11 IHC Tips
Troubleshoot PTPN11 staining in paraffin sections by checking retrieval, cell identity, localisation and matched controls before interpreting DAB intensity.
What retrieval conditions should I try first for weak PTPN11 staining?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin sections (datasheet M00150-1). The selected human colon example used this retrieval before 1:50 primary antibody incubation overnight at 4°C (datasheet M00150-1). If staining is weak, compare heating and cooling conditions on adjacent sections while keeping antibody incubation and detection consistent (standard IHC practice). Only then test another retrieval buffer as a fallback, alongside a matched positive control, because retrieval changes can affect signal and background (standard IHC practice). Colon glandular cells provide a documented positive comparator (HPA: High in colon glandular cells).
How should I assess whether fixation caused weak PTPN11 staining?
The selected tissue image describes a paraffin-embedded human colon section but does not state its fixative, so PTPN11-specific fixation sensitivity is unknown (datasheet M00150-1). Record each specimen’s fixative and fixation interval, then compare similarly processed sections before attributing a signal difference to fixation (standard IHC practice). Keep retrieval at EDTA pH 8.0 and the primary dilution at 1:50 during that comparison (datasheet M00150-1). Include a colon glandular-cell reference on each run to check whether staining is reproducible (HPA: High in colon glandular cells; standard IHC practice). Do not infer fixation tolerance from tissue expression patterns or protein topology alone (standard IHC practice).
Should PTPN11 appear in the cytoplasm, nucleus or cell membrane?
Expect predominantly cytoplasmic tissue staining, while assessing nuclear signal separately because both compartments are reported for PTPN11 (HPA: general cytoplasmic expression; UniProt Q06124: Cytoplasm, Nucleus). In the selected colon context, inspect glandular cells first and compare their staining with surrounding tissue (HPA: High in colon glandular cells). A membrane-only outline needs scrutiny: PTPN11 has no transmembrane segment, although it participates in receptor-associated signalling (UniProt Q06124: topology and function). The nucleoli rim pattern comes from subcellular ICC/IF observations and should not be imposed as an IHC scoring requirement (HPA: subcellular localisation). Check serial sections and no-primary controls before accepting an unexpected compartment pattern (standard IHC practice).
Could isoforms or epitope location explain inconsistent PTPN11 staining?
PTPN11 has 3 listed isoforms, so obtain the antibody’s mapped immunogen or epitope before treating staining as pan-isoform detection (UniProt Q06124: isoforms; standard IHC practice). The protein contains SH2 domains at residues 6–102 and 112–216, and a phosphatase domain at 247–517 (UniProt Q06124: domains). Reported phosphotyrosines include residues 62, 66, 542 and 580 (UniProt Q06124: modified residues). These annotations identify questions to check against the actual epitope; they do not establish that this antibody distinguishes a modification or isoform (standard IHC practice). Compare adjacent sections under the same EDTA pH 8.0 retrieval before assigning biological meaning to a staining difference (datasheet M00150-1; standard IHC practice).
How can I compare PTPN11 immunofluorescence with the tissue IHC result?
For multiplex IF, pair PTPN11 with an epithelial marker such as pan-cytokeratin when examining the documented colon glandular-cell population (HPA: High in colon glandular cells; standard IF practice). Choose a spectrally separated, preferably far-red fluorophore and inspect an unstained section for tissue autofluorescence before interpreting weak signal (standard IF practice). PTPN11 is intracellular and has no transmembrane segment, so permeabilise when the antibody epitope requires access to the cytosol or nucleus (UniProt Q06124: localisation and topology; standard IF practice). Determine that access requirement from the antibody’s epitope information rather than assuming its exact location (standard IF practice). The HPA nucleoli rim observation is ICC/IF evidence, whereas the selected paraffin-section image establishes chromogenic IHC conditions (HPA: subcellular localisation; datasheet M00150-1).
How do I distinguish diffuse PTPN11 signal from chromogenic background?
The selected colon example used 10% goat serum blocking, 1:50 rabbit primary antibody overnight at 4°C, and DAB development (datasheet M00150-1). Check a no-primary control to reveal secondary-reagent binding and endogenous colour before judging diffuse staining as PTPN11 (standard IHC practice). An endogenous peroxidase block is a general HRP–DAB workflow step; its use is not specified in the selected caption (standard IHC practice; datasheet M00150-1). If background persists, compare primary-antibody dilution and wash conditions on adjacent sections while preserving the same retrieval and development conditions (standard IHC practice). Evaluate cytoplasmic signal in identifiable viable cells against the control, since general cytoplasmic expression is reported (HPA: tissue IHC profile; standard IHC practice).
What is a reproducible way to score PTPN11 IHC staining? ⚠ ANSWER MARKED FOR VERIFICATION
Define the compartment and cell population before scoring; for colon, analyse viable glandular cells and record cytoplasmic and nuclear staining separately (HPA: High in colon glandular cells; UniProt Q06124: localisation; standard IHC practice). An H-score combines the percentage of cells at intensity grades 0–3 into a 0–300 score (standard IHC practice). Alternatively, report percentage positive cells or positive-cell density per mm², with the threshold fixed before comparing groups (standard IHC practice). Normalise counts to viable glandular-cell number or analysed glandular area, and use the same reference tissue and DAB settings across runs (standard IHC practice). Document excluded necrotic and edge regions so their staining does not shift the denominator (standard IHC practice).
When is an unusual PTPN11 staining pattern likely to be artefactual?
Give most weight to reproducible staining in viable, identifiable cells; colon glandular cells are a documented high-expression population (HPA: High in colon glandular cells; standard IHC practice). Cytoplasmic staining fits the tissue profile, and nuclear staining remains biologically plausible, but an exclusive membrane outline warrants control review (HPA: tissue IHC profile; UniProt Q06124: localisation and topology). Inspect edge and necrotic regions for uneven DAB deposition, and compare them with a no-primary control and an endogenous peroxidase block (standard IHC practice). Skeletal-muscle myocytes were not detected in the HPA tissue panel, yet UniProt describes high expression in skeletal muscle; avoid treating one myocyte result as a universal negative control (HPA: skeletal-muscle myocytes; UniProt Q06124: tissue specificity). HPA rates tissue staining as Approved with medium RNA consistency, so confirm unexpected conclusions using matched sections and controls (HPA: reliability; standard IHC practice).
Boster reagents
Best PTPN11 / Tyrosine-protein phosphatase non-receptor type 11 IHC Antibodies
Anti-PTPN11 IHC images cover human colon, colon cancer, lung and heart, plus mouse brain; IF images show U251 and PC-3 cells (catalog image captions). Listed reactivity spans human, mouse and rat (catalog reactivity).
Real IHC data
Anti-SHP2 PTPN11 Rabbit Monoclonal Antibody
Cat # M00150-1
Real IHC data
Anti-SHP2/PTPN11 Antibody ® (monoclonal, 2E6)
Cat # M00150-2
Real IHC data
Anti-SHP2/PTPN11 Antibody ®
Cat # PA1860
Real IHC data
Anti-SHP2 PTPN11 Rabbit Monoclonal Antibody
Cat # M00150
M00150 shows paraffin-section IHC in human heart, while M00150-1 shows paraffin-section IHC in human colon and mouse brain (respective IHC captions). M00150-2 shows paraffin-section IHC in human colon cancer and IF in U251 cells; PA1860 shows paraffin-section IHC in human lung and IF in PC-3 cells (respective image captions).
Which to pick: For tissue IHC, choose M00150-1 when its rabbit monoclonal format and human colon and mouse brain paraffin-section examples fit the study (catalog: host and clone; M00150-1 IHC captions); the captions do not report a fixative (M00150-1 IHC captions). For IF/ICC, choose M00150-2 for a mouse monoclonal with a U251 IF image, or PA1860 for a rabbit antibody with a PC-3 IF image (catalog: hosts, applications and IF captions). For cross-species planning, M00150-1, M00150-2 and PA1860 list human, mouse and rat reactivity; their own IHC captions show human and mouse, human and mouse, and human tissue, respectively (catalog: reactivity and respective IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q06124 (PTN11_HUMAN, Tyrosine-protein phosphatase non-receptor type 11).
- Human Protein Atlas. PTPN11 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. PTPN11 subcellular location (ICC-IF): Mainly localized to the nucleoli rim. In addition localized to the nucleoplasm, cytosol and actin filaments..
- Human Protein Atlas. PTPN11 antibody validation summary (1 antibodies).
- MiR-204 silencing in intraepithelial to invasive cutaneous squamous cell carcinoma progression. Molecular cancer 2016 — PMC4960761.
- Undiagnosed RASopathies in infertile men. Frontiers in endocrinology 2024 — PMC11035881.
- Curcumin inhibits proliferation of hepatocellular carcinoma cells by blocking PTPN1 and PTPN11 expression. Oncology letters 2023 — PMC10272960.
- A pan-cancer analysis confirms PTPN11's potential as a prognostic and immunological biomarker. Aging 2022 — PMC9320542.
- PubMed PMID:1281790 — UniProt-cited evidence.
- PubMed PMID:1280823 — UniProt-cited evidence.
- PubMed PMID:8216283 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PTPN11 (Tyrosine-protein phosphatase non-receptor type 11). Expected localisation Cytoplasmic in tissue IHC (HPA tissue IHC); nucleus annotated (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet M00150-1). Validated IHC antibody: M00150-1 at 1:50 (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative Skeletal muscle. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colon tissue; fixative not specified (datasheet M00150-1); 2. Fixation: Image fixative and duration unreported (datasheet M00150-1); 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 M00150-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet M00150-1); 8. Primary antibody: Rabbit monoclonal (clone GBO-16) anti-PTPN11, 1:50 (datasheet M00150-1); 9. Primary incubation: Overnight at 4 °C (datasheet M00150-1). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific). Selected-image fixative and duration unreported (datasheet M00150-1); verify before use.; Caveat: Skeletal myocytes lack staining despite reported muscle expression (HPA tissue IHC; UniProt); Isoform / epitope: 3 isoforms; map the antibody epitope across them (UniProt); Regulation: Expression regulation unreported (UniProt). Evidence: UniProt Q06124, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoli rim. In addition localized to the…, Datasheet M00150-1, PMC4960761, PMC11035881. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PTPN11/immunohistochemistry-ihc-guide.