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PMS2 / Mismatch repair endonuclease PMS2 · IHC design guide
Design Immunohistochemistry for PMS2
Plan PMS2 staining in paraffin sections around the nuclear pattern reported in most tissues (HPA tissue IHC). This guide identifies cell-specific control choices (HPA tissue IHC) and flags MLH1-dependent stability when interpreting weak signal (UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PMS2 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 | Nuclear staining in most tissues (HPA tissue IHC) | |
| Staining pattern | Nuclear staining across most tissue cell types (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen) | |
| Positive control | Cerebellum+4 more · see all | |
| Negative control | Adipose tissue+3 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | MLH1 loss may reduce PMS2 signal through reduced stability (UniProt) | |
| Regulation | Stability depends on MLH1 binding (UniProt) | |
| Isoform / epitope | 4 isoforms; epitope coverage is unspecified (UniProt) |
Section 1
Recommended PMS2 IHC & IF Protocols
The catalog antibody protocol is followed by published PMS2 IHC methods for colorectal carcinoma and tumor tissue (PMC13018393; PMC3273660; PMC8011511).
| Sample | Paraffin-embedded human tonsil tissue; fixative not specified (datasheet M01028-1) |
| Fixation | Image fixative and duration unreported (datasheet M01028-1); 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 Tris-EDTA buffer, pH 9.0, 20 min at 95–98 °C (standard rule: nuclear 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 monoclonal (clone AEH-16) anti-PMS2, 1:50 (datasheet M01028-1) |
| 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 | PMS2-positive staining in purkinje cells of cerebellum (HPA tissue IHC: High). HPA tissue profile: Nuclear expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0 retrieval at 95–98 °C for 20 min (page retrieval rule: nuclear antigen; UniProt P54278: nucleus).
Section 2
What Is the Expected PMS2 Staining Pattern?
PMS2 should appear predominantly in nuclei across most tissues (UniProt P54278: nucleus; HPA tissue IHC: nuclear expression in most tissues). Purkinje cells, cerebral cortical neurons, and spermatogonia show high staining; several epithelial and glandular populations show medium staining (HPA tissue IHC). HPA rates the tissue profile Approved, with medium consistency between staining and RNA data (HPA tissue IHC). PMS2 has no transmembrane segment (UniProt P54278: topology).
| Distinct nuclear chromogen in Purkinje cells, cerebral cortical neurons, or spermatogonia. | This matches the expected compartment and HPA's high staining levels in those cells (UniProt P54278: nucleus; HPA tissue IHC: High). Assess individual nuclei against adjacent cells; a uniformly dark section is harder to interpret (general IHC practice). |
| Nuclear staining in appendix or breast glandular cells, bronchial respiratory epithelium, or caudate glia. | Medium staining is consistent with the reported cell-specific pattern (HPA tissue IHC: Medium). Compare the relevant cell population, since intensity across an entire tissue section can obscure which cells carry the signal (general IHC practice). |
| Predominantly cytoplasmic staining, with little convincing nuclear signal. | This conflicts with the expected IHC pattern (UniProt P54278: nucleus; HPA tissue IHC: nuclear expression in most tissues). Review background and antibody specificity before calling the section positive. HPA's uncertain additional cytosolic ICC-IF location does not establish a cytoplasmic IHC pattern (HPA subcellular ICC-IF). |
| Strong staining in adipocytes, cholangiocytes, alveolar cells, or soft-tissue fibroblasts. | Those specific populations are reported as not detected, making prominent signal a reason to investigate cross-reactivity or endogenous detection activity (HPA tissue IHC: Not detected; general IHC practice). The HPA result is a reference pattern, not proof that every specimen must be negative. |
| Diffuse staining across nuclei, cytoplasm, and surrounding tissue, or no staining in a known-positive control. | Diffuse signal limits compartment-based interpretation; absent control signal leaves a negative result uninterpretable (general IHC practice). A section containing an HPA high-staining cell population can provide a reference, provided that population is present and identifiable (HPA tissue IHC: High). |
💡Expected PMS2 appearanceCall a result positive when staining is predominantly nuclear in the relevant cells, potentially strong in Purkinje cells, cerebral cortical neurons, or spermatogonia; diffuse cytoplasmic color or strong signal in HPA not-detected cell populations warrants scrutiny (UniProt P54278: nucleus; HPA tissue IHC: High and Not detected; general IHC practice).
| Tissue and cell selection | HPA reports High staining in Purkinje cells, cerebral cortical neurons, and spermatogonia, but Not detected in adipocytes, cholangiocytes, alveolar cells, and soft-tissue fibroblasts (HPA tissue IHC). Match the comparison to the named cell type, since a tissue label alone does not describe every cell in a section. |
| Strength of the tissue reference | The profile is Approved, with medium consistency between antibody staining and RNA expression data (HPA tissue IHC). Use its reported levels as interpretation guides rather than absolute thresholds for an individual specimen. |
| Antibody validation | CAB010235 has Approved IHC status; HPA070310 has no IHC status in the supplied antibody record (HPA antibodies). ICC support for either antibody does not establish IHC performance (HPA antibodies). |
| Isoforms and epitope coverage | Four isoforms are listed, but the payload does not map an IHC antibody's epitope to them (UniProt P54278: isoforms 1–4). A difference in staining cannot be assigned to isoform recognition from these records alone. |
| Does the IF/ICC result change the IHC call? | No: HPA supports nucleoplasmic localization in ICC-IF and marks additional cytosolic localization uncertain (HPA subcellular ICC-IF). That observation informs compartment review, while this paraffin-section guide relies on the IHC tissue pattern for its positive call (HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| No nuclear signal in an expected high-staining cell population. | The staining run may have failed, or the chosen section may lack identifiable target cells (general IHC practice; HPA tissue IHC: High in the named populations). | Confirm the target cells on the counterstained section and inspect a known-positive control run with the same reagents. Review the catalog antibody's IHC-P instructions and the run's retrieval, antibody incubation, and detection steps (general IHC practice). |
| Signal appears mainly cytoplasmic. | Background or nonspecific binding is possible; the predominant compartment conflicts with nuclear IHC expression (general IHC practice; HPA tissue IHC: nuclear expression in most tissues). | Compare nuclear and cytoplasmic staining in the same cells, then review blocking, antibody concentration, and detection controls (general IHC practice). Do not use the uncertain cytosolic ICC-IF observation as confirmation of cytoplasmic IHC staining (HPA subcellular ICC-IF). |
| Strong color appears in HPA not-detected cell populations. | Cross-reactivity or endogenous detection activity may contribute, although tissue differences and assay conditions also require review (HPA tissue IHC: Not detected; general IHC practice). | Verify the cell identity and run a control that omits the primary antibody to assess detection-related signal. Compare localization with a known-positive nuclear control before assigning PMS2 positivity (general IHC practice; UniProt P54278: nucleus). |
| Diffuse color obscures nuclei throughout the section. | Excess background can arise from nonspecific binding, detection chemistry, or insufficient washing (general IHC practice). It prevents a reliable comparison with the nuclear reference pattern (HPA tissue IHC). | Inspect the no-primary control, then review blocking, wash steps, antibody concentration, and chromogen development for the assay (general IHC practice). Reassess only when individual nuclei and cell types can be distinguished. |
| A weakly stained section is called negative. | Some named populations are reported Low, while others are Medium; a single intensity cutoff can misclassify a cell-specific result (HPA tissue IHC: Low and Medium). | Identify the exact cell population and compare it with its HPA level. Use a high-staining control to check that the run worked, then score nuclear localization alongside intensity (HPA tissue IHC: High; general IHC practice). |
| An ICC-IF image shows cytosolic signal that seems inconsistent with IHC. | HPA supports the nucleoplasm as the main ICC-IF location but labels its additional cytosolic location uncertain (HPA subcellular ICC-IF). The two assays also present tissue and cells differently (general IHC/IF practice). | Interpret the paraffin IHC section against its nuclear tissue pattern and controls (HPA tissue IHC; general IHC practice). Address ICC-IF assay settings and images in the separate IF/ICC guide. |
Experiment evidence
IHC & IF images showing PMS2 staining
M01028-1 · IHCImmunohistochemical analysis of paraffin-embedded human tonsil, using PMS2 Antibody.
M01028-1 · IFImmunofluorescent analysis using the Antibody at 1:50 dilution.
M01028-3 · IHCHuman rectal carcinoma tissue was stained with anti-PMS2 rabbit Antibody
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000122512-PMS2/tissue/cerebral+cortex#imid_3020336
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000122512-PMS2/tissue/colon#imid_3020270
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000122512-PMS2/tissue/liver#imid_3020263
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000122512-PMS2/tissue/kidney#imid_3020272
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB010235; green = PMS2, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB010235; green = PMS2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PMS2 IHC & IF
🧪Run testis first; spermatogonia should show nuclear PMS2 staining (HPA: High in spermatogonia; UniProt P54278: nucleus). Run adipose tissue as the negative tissue, assessing adipocytes for absent staining (HPA: Not detected in adipocytes); on the testis slide, unstained nuclei outside the spermatogonial population can indicate background, but those cells are not established as PMS2-negative by the supplied HPA row.
Positive control tissue: Cerebellum (Purkinje cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PMS2 in A-431, MCF-7, U2OS, HaCaT, SiHa, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control; a host-matched isotype control for a monoclonal primary or matched nonimmune IgG for a polyclonal primary; and a PMS2 knockout control or validated peptide block. For chromogenic testis IHC, quench endogenous peroxidase and check the control slide for residual background (standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected paraffin-section caption does not state a fixative (M01028-1 caption: fixative not stated). Retrieval dependence is unreported, so optimize antigen retrieval empirically for paraffin sections; the supplied evidence does not establish frozen sections or IF as easier (M01028-1 caption: paraffin-embedded tonsil; HPA: ICC-IF images available). Crowded germ-cell nuclei can complicate scoring in testis, so assess staining against cell morphology and the counterstain (standard histology practice).
HPA tissue IHC evidence for PMS2
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 |
|---|---|---|---|---|
| Cerebellum | Purkinje cells | High | Protein (IHC) | HPA → |
| Cerebral cortex | Neuronal cells | High | Protein (IHC) | HPA → |
| Testis | Spermatogonia cells | High | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Liver | Cholangiocytes | Not detected | Protein (IHC) | HPA → |
| Lung | Alveolar cells | Not detected | Protein (IHC) | HPA → |
| Soft tissue | Fibroblasts | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced PMS2 IHC Tips
Troubleshoot PMS2 staining by checking nuclear signal, tissue controls, and processing variables before interpreting apparent loss of expression (UniProt P54278; HPA tissue IHC).
How should I retrieve PMS2 in paraffin sections when nuclear staining is weak?
Start with Tris-EDTA at pH 9.0, heated to 95–98 °C for 20 min (page retrieval specification). Allow sections to cool consistently, then compare retrieved and unretrieved serial sections with the same antibody and detection conditions (standard IHC practice). Score nuclear signal in viable cells, since PMS2 is nuclear and HPA reports nuclear expression in most tissues (UniProt P54278 localisation; HPA tissue IHC). If staining remains weak, vary retrieval time on adjacent sections while checking for tissue damage and rising background (standard IHC practice). Record each condition and use the one that preserves morphology and specific nuclear contrast (standard IHC practice).
Can fixation explain inconsistent PMS2 staining between paraffin blocks?
Target-specific fixation sensitivity is unknown from the supplied evidence, so document each block’s fixative, fixation duration, and processing history before comparing results. The selected antibody image shows paraffin-embedded human tonsil, but its caption does not state a fixative (caption: M01028-1). For a controlled investigation, process matched samples under defined conditions, such as 10% neutral buffered formalin for 6 versus 24 h, and keep retrieval and detection identical (standard IHC practice). Examine morphology and nuclear signal together, using a positive internal control in each section where available (standard IHC practice). Do not attribute differences to PMS2 fixation sensitivity without that comparison.
What staining pattern should count as correctly localised PMS2?
Prioritise staining within morphologically intact nuclei: UniProt places PMS2 in the nucleus, and HPA describes nuclear expression in most tissues (UniProt P54278 localisation; HPA tissue IHC). HPA specifically supports nucleoplasmic localisation, while its additional cytosolic localisation is uncertain (HPA subcellular). Compare nuclear and cytoplasmic signal separately in at least 2 representative fields, keeping exposure or chromogen development consistent across sections (standard IHC practice). Strong cytoplasmic staining without corresponding nuclear signal warrants checks of antibody concentration, blocking, and section quality before interpretation (standard IHC practice). Use a nuclear counterstain to identify the compartment being scored (standard IHC practice).
Could PMS2 isoforms or epitope masking explain discordant nuclear staining?
PMS2 has 4 annotated isoforms, but the supplied evidence does not identify the catalog antibody’s epitope or establish which isoforms it detects (UniProt P54278 isoforms; supplied catalog evidence). Request or inspect an epitope map before interpreting a negative section as loss of all PMS2 products (standard antibody validation practice). UniProt lists phosphothreonine at residues 573 and 597; their effect on this antibody’s staining is unknown (UniProt P54278 modified residues). Compare serial sections with an independently validated antibody targeting a documented, different region if available (standard IHC practice). Keep retrieval and controls matched so an antibody-dependent difference remains interpretable (standard IHC practice).
How can I assess PMS2 by multiplex IF alongside a cell-type marker?
For the separate IF/ICC workflow, pair PMS2 with a validated spermatogonia marker when examining testis, where HPA reports high PMS2 staining in spermatogonia (HPA tissue IHC). Assign PMS2 a far-red fluorophore when tissue autofluorescence compromises shorter-wavelength channels, and include single-stain controls for bleed-through (standard IF practice). PMS2 is nuclear with no annotated transmembrane segment, so permeabilise cells sufficiently to access the nuclear compartment; 0.1% Triton X-100 for 5 min is a starting condition to validate (UniProt P54278 localisation and topology; standard IF practice). Check nuclear morphology and marker overlap in separate channels before interpreting merged images (standard IF practice).
What should I check when PMS2 chromogenic staining appears diffuse or granular?
First compare a no-primary control with the stained section to separate detection-system background from antibody-associated signal (standard IHC practice). For peroxidase detection, a 3% hydrogen peroxide block for 10 min is a general starting condition, followed by a controlled DAB development time (standard IHC practice). Recheck wash steps, antibody concentration, and damaged or folded areas if brown deposit extends across nuclei and cytoplasm (standard IHC practice). Genuine PMS2 signal should be assessed chiefly in nuclei; HPA supports nucleoplasmic localisation and regards additional cytosolic localisation as uncertain (UniProt P54278 localisation; HPA subcellular). Compare the same tissue region across controls before changing multiple variables (standard IHC practice).
How should I score heterogeneous PMS2 nuclear staining across a section? ⚠ ANSWER MARKED FOR VERIFICATION
Define viable regions before scoring and exclude folds, necrosis, and section edges that can distort staining (standard IHC practice). Record the percentage of positive nuclei and intensity from 0–3; an H-score sums intensity multiplied by the percentage at each intensity, yielding 0–300 (standard IHC scoring practice). Score at least 100 eligible cells per prespecified region when feasible, and normalise counts to the number of viable nuclei assessed (standard IHC practice). Report regions separately if staining varies, with a same-slide internal control where available (standard IHC practice). HPA’s predominantly nuclear profile supports nuclear rather than whole-cell scoring (HPA tissue IHC).
When does absent PMS2 staining indicate loss rather than an IHC artefact?
Interpret apparent loss only when viable target cells lack nuclear staining while appropriate internal control nuclei retain it (standard IHC interpretation; UniProt P54278 localisation). Exclude edge effects, necrosis, folds, and endogenous peroxidase signal by reviewing morphology and a no-primary control (standard IHC practice). PMS2 forms a heterodimer with MLH1, and their interaction supports both partners’ stability, so related mismatch-repair staining can inform follow-up interpretation (UniProt P54278 subunit). HPA describes nuclear expression in most tissues but reports only medium consistency between staining and RNA data (HPA tissue IHC). Repeat a technically equivocal result with controlled retrieval and detection before assigning biological loss (standard IHC practice).
Boster reagents
Best PMS2 / Mismatch repair endonuclease PMS2 IHC Antibodies
Both antibodies list human IHC and IF applications (catalog applications/reactivity); both have IHC images, while only M01028-1 has an IF image (catalog image captions).
Real IHC data
Anti-PMS2 Rabbit Monoclonal Antibody
Cat # M01028-1
Real IHC data
Anti-PMS2 Rabbit Monoclonal Antibody
Cat # M01028-3
M01028-1 lists human IHC and IF applications, with IHC shown on paraffin-embedded human tonsil (catalog applications/reactivity; M01028-1 IHC caption). M01028-3 lists human IHC and IF applications, with IHC shown on human rectal carcinoma tissue; its processing and fixative are unreported (catalog applications/reactivity; M01028-3 IHC caption).
Which to pick: For paraffin-section IHC, start with M01028-1 at 1:50, matching its tonsil image; the fixative is unreported (M01028-1 IHC caption; datasheet: 1:50). For IF/ICC, choose M01028-1 because it lists both applications and has an IF image, though the IF sample type is unreported; M01028-3 lists IF but has no IF image (catalog applications; catalog IF captions). Neither SKU has documented cross-species reactivity: both list Human only (catalog reactivity).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P54278 (PMS2_HUMAN, Mismatch repair endonuclease PMS2).
- Human Protein Atlas. PMS2 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. PMS2 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
- Human Protein Atlas. PMS2 antibody validation summary (2 antibodies).
- MSH6 and PMS2 expression in colorectal carcinoma. Bioinformation 2025 — PMC13018393.
- Identification of cancer patients with Lynch syndrome: clinically significant discordances and problems in tissue-based mismatch repair testing. Cancer prevention research (Philadelphia, Pa.) 2012 — PMC3273660.
- Characteristics of colorectal carcinoma patients with PMS2 defects detected by immunohistochemistry. European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP) 2021 — PMC8011511.
- The role of MLH1, MSH2 and MSH6 in the development of colorectal cancer in Uganda. BMC cancer 2025 — PMC12036241.
- PubMed PMID:8072530 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:12853948 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PMS2 (Mismatch repair endonuclease PMS2). Expected localisation Nuclear staining in most tissues (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: M01028-1 at 1:50 (the product's own IHC validation image is shown). Controls (HPA): positive Cerebellum (Purkinje cells); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded human tonsil tissue; fixative not specified (datasheet M01028-1); 2. Fixation: Image fixative and duration unreported (datasheet M01028-1); 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-induced epitope retrieval in Tris-EDTA buffer, pH 9.0 , 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 monoclonal (clone AEH-16) anti-PMS2, 1:50 (datasheet M01028-1); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: MLH1 loss may reduce PMS2 signal through reduced stability (UniProt); Isoform / epitope: 4 isoforms; epitope coverage is unspecified (UniProt); Regulation: Stability depends on MLH1 binding (UniProt). Evidence: UniProt P54278, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet M01028-1, PMC13018393, PMC3273660. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PMS2/immunohistochemistry-ihc-guide.