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PMS2 / Mismatch repair endonuclease PMS2 · IHC design guide
Design Immunohistochemistry for PMS2
Plan chromogenic PMS2 IHC around nuclear staining in most tissues (HPA tissue IHC). Use spermatogonia or Purkinje cells as high-staining references when available (HPA tissue IHC), and evaluate nuclear signal with an IHC-validated antibody.
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 in most tissues (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in most tissues, including spermatogonia (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 sections (standard IHC practice; not target-specific) | |
| Caveat | MLH1 loss may reduce PMS2 staining (UniProt) | |
| Regulation | MLH1 binding stabilizes PMS2 (UniProt) | |
| Isoform / epitope | 4 isoforms; check epitope coverage (UniProt) |
Section 1
Recommended PMS2 IHC & IF Protocols
The catalog antibody protocol and one published colorectal carcinoma IHC protocol provide starting points for PMS2 staining (PMC13018393).
| 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 HIER at pH 9.0, 95–98 °C for 20 min (page retrieval rule: nuclear antigen; UniProt: nucleus).
Section 2
What Is the Expected PMS2 Staining Pattern?
PMS2 is nuclear (UniProt P54278) and shows nuclear expression in most tissues (HPA tissue IHC: Approved; medium consistency with RNA). Expect the clearest staining in Purkinje cells, cerebral cortical neuronal cells and spermatogonia, each reported High by HPA (HPA tissue IHC). PMS2 has no transmembrane segment (UniProt P54278 topology), so a membrane rim is not its expected pattern.
| Distinct nuclear chromogen in Purkinje cells, cortical neuronal cells or spermatogonia (HPA tissue IHC: High). | This matches PMS2's nuclear location (UniProt P54278) and HPA's observed cell patterns (HPA tissue IHC). Judge intensity against nuclei in the same run; High is an HPA category, not a universal staining threshold (HPA tissue IHC; general IHC practice). |
| Strong cytoplasmic or membrane staining with little nuclear signal in an IHC section (HPA tissue IHC: nuclear pattern). | The compartment conflicts with the expected IHC pattern (HPA tissue IHC; UniProt P54278). Review background and detection controls before assigning PMS2 positivity (general IHC practice). HPA's uncertain cytosolic ICC-IF observation does not establish a cytoplasmic IHC pattern (HPA subcellular). |
| Prominent signal in adipocytes or alveolar cells, especially without nuclear staining in expected positive cells (HPA tissue IHC). | HPA reports PMS2 as Not detected in those cell types (HPA tissue IHC). Consider cross-reactivity or endogenous detection activity (general IHC practice); HPA's observations alone cannot identify which caused the signal. |
| Diffuse color covers nuclei, cytoplasm and tissue spaces (general IHC practice). | This obscures whether nuclei carry a discrete PMS2 signal (HPA tissue IHC: nuclear pattern). Compare a no-primary control and inspect blocking, washing and detection background (general IHC practice) before scoring cell types. |
| No nuclear signal in a section containing well-preserved Purkinje cells, cortical neuronal cells or spermatogonia (HPA tissue IHC: High). | A technical false negative is possible (general IHC practice). Check section integrity and the antibody and detection run; HPA reports High staining in these cells, but its Approved rating has medium consistency with RNA (HPA tissue IHC). |
💡Expected PMS2 appearanceCall a result positive when identifiable nuclei show discrete staining in HPA-reported cells, strongest in Purkinje cells, cortical neuronal cells or spermatogonia (HPA tissue IHC: High); isolated membrane staining or broad cytoplasmic color is suspicious (UniProt P54278 topology; HPA tissue IHC: nuclear pattern).
| Cell-specific reference intensity (HPA tissue IHC) | HPA reports Medium staining in adrenal, appendix and breast glandular cells, bronchial respiratory epithelium and caudate glia, alongside High examples (HPA tissue IHC). Interpret intensity by cell identity; weak staining in another cell type cannot be judged against a single High reference (general IHC practice). |
| MLH1 association (UniProt P54278 subunit) | PMS2 forms MutL alpha with MLH1, and their interaction supports both partners' stability (UniProt P54278 subunit). This biology can inform interpretation, but the supplied HPA patterns do not establish how a given specimen's MLH1 status will alter its PMS2 IHC signal. |
| Isoforms and antibody recognition (UniProt P54278) | UniProt lists four PMS2 isoforms (UniProt P54278). No antibody epitope or isoform recognition data are supplied, so an unusual staining result cannot be attributed to a particular isoform from this record. |
| IF/ICC Q: Is cytosolic PMS2 signal expected? | A: HPA supports nucleoplasmic ICC-IF localization and labels its additional cytosolic localization uncertain (HPA subcellular). Treat nuclear signal as the stronger localization reference; this ICC-IF observation does not define an IHC staining or protocol option (HPA subcellular; HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected positive nuclei are blank (HPA tissue IHC: High examples). | The run may lack usable antigen or detectable signal (general IHC practice); no PMS2-specific fixation sensitivity is reported in the supplied UniProt or HPA record. | Check tissue preservation, antigen retrieval and antibody and detection steps against a known positive section in the same run (general IHC practice). Do not infer a PMS2-specific retrieval setting from HPA staining levels. |
| All cells have similarly faint nuclear color (general IHC practice). | Background may make cell-specific staining hard to separate (general IHC practice). HPA reports different intensities across cell types (HPA tissue IHC). | Compare the no-primary control, then assess nuclear contrast in a High reference cell population and a low or Not detected population (HPA tissue IHC; general IHC practice). |
| Brown color appears outside cells or across the section (general IHC practice). | Detection background or nonspecific color can obscure the HPA-reported nuclear pattern (general IHC practice; HPA tissue IHC). | Inspect no-primary and detection controls; review blocking and wash steps before changing how PMS2-positive nuclei are scored (general IHC practice). |
| Cytoplasm dominates while nuclei remain pale (HPA tissue IHC: nuclear pattern). | This is discordant with UniProt's nuclear location and HPA's tissue IHC profile (UniProt P54278; HPA tissue IHC); the cause is unresolved. | Check nuclear counterstain and section morphology, then compare positive and no-primary controls (general IHC practice). Do not use uncertain ICC-IF cytosol as validation for an IHC call (HPA subcellular). |
| Adipocytes, cholangiocytes, alveolar cells or soft-tissue fibroblasts stain strongly (HPA tissue IHC: Not detected). | The result differs from HPA's observations; cross-reactivity or endogenous detection activity is possible (HPA tissue IHC; general IHC practice). | Verify cell identity and localization, inspect detection controls, and compare expected positive nuclei in the same run (general IHC practice; HPA tissue IHC). |
| A specimen is called PMS2-negative from one unstained cell population (general IHC practice). | HPA reports Low or Not detected staining in several cell types despite nuclear expression in most tissues (HPA tissue IHC). | Score identified cell populations separately and confirm that an expected positive control stained in the run (HPA tissue IHC; general IHC practice). |
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 cerebellum first and look for nuclear staining in Purkinje cells (HPA: High in Purkinje cells; UniProt P54278: nucleus). Use adipose tissue as the negative comparator, focusing on adipocytes (HPA: Not detected in adipocytes); on the cerebellum slide, treat cells without nuclear staining as internal background, without assuming they are biologically PMS2-negative.
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; an isotype control matched to the primary antibody’s host species and clonality; and a PMS2-knockout specimen if available (standard IHC practice). Quench endogenous peroxidase for chromogenic detection, and compare the cerebellum control slide for background signal (standard IHC practice).
⚠️Feasibility: A PMS2-specific fixation window or fixation effect is unreported, and the selected M01028-1 paraffin-section tonsil caption does not state a fixative (selected tissue-IHC caption). Antigen-retrieval dependence is unreported; heat-induced retrieval can be optimized for paraffin IHC, but the supplied evidence does not establish whether frozen sections or IF are easier (standard IHC practice; selected tissue-IHC caption). Purkinje-cell lipofuscin can resemble brown chromogen, so compare signal with the no-primary control (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
For PMS2 chromogenic IHC in paraffin sections, assess nuclear staining with matched controls and document processing conditions before comparing samples (UniProt P54278; HPA tissue IHC).
How should I retrieve PMS2 when nuclear staining is weak in paraffin sections?
Use Tris-EDTA pH 9.0 heat-induced antigen retrieval at 95–98 °C for 20 min (page retrieval rule: nuclear antigen). Let sections cool in the retrieval solution, then wash consistently before blocking so differences between runs do not masquerade as PMS2 variation (standard IHC practice). Include a known staining control alongside the test section; the selected antibody has a paraffin-embedded human tonsil IHC image, although its fixation conditions are unreported (selected IHC caption: M01028-1). If nuclear staining remains weak, vary retrieval duration on parallel sections while keeping detection conditions fixed (standard IHC practice). Score recovery in nuclei rather than diffuse cytoplasm, because PMS2 is nuclear and its supported HPA location is nucleoplasmic (UniProt P54278; HPA subcellular).
Could fixation explain weak or uneven PMS2 staining?
The paraffin-embedded human tonsil caption for M01028-1 does not state a fixative, so target-specific fixation sensitivity is unknown (selected IHC caption: M01028-1). Record the actual fixative, delay before fixation, and fixation duration for each specimen before comparing chromogenic intensity (standard IHC practice). When processing varies, stain sections from the same block together and compare preserved areas with similar morphology (standard IHC practice). Test retrieval changes on matched sections rather than assigning a weak result to PMS2 biology from fixation history alone (standard IHC practice). HPA reports nuclear expression in most tissues, but that pattern does not establish how this antibody responds to any fixation condition (HPA tissue IHC).
Should PMS2 staining be nuclear, cytoplasmic, or both?
Treat crisp nuclear staining as the primary PMS2 pattern in chromogenic paraffin-section IHC (UniProt P54278: nucleus; HPA subcellular: supported nucleoplasm). HPA also lists cytosol as an uncertain additional location, so isolated cytoplasmic color deserves cautious review rather than automatic scoring as positive (HPA subcellular). PMS2 has no annotated transmembrane segment or signal peptide, making a membrane-bound staining pattern inconsistent with the supplied protein record (UniProt P54278 topology and processing). Compare suspected positive cells with nearby internal nuclei under the same retrieval and detection conditions (standard IHC practice). If cytoplasmic color dominates, inspect morphology, chromogen deposition, and the negative control before interpreting the pattern (standard IHC practice).
How do isoforms and epitope uncertainty affect PMS2 IHC interpretation?
PMS2 has 4 listed isoforms, but the supplied evidence does not map the catalog antibody’s epitope to any of them (UniProt P54278 isoforms; selected IHC caption: M01028-1). Consequently, staining alone cannot establish which isoform contributes to a positive nucleus or whether a negative nucleus lacks all isoforms (UniProt P54278 isoforms; standard IHC interpretation). The record lists phosphothreonines at residues 573 and 597, without evidence that either changes this antibody’s staining (UniProt P54278 modified residues). Keep retrieval and detection matched when comparing specimens, and seek antibody-specific epitope documentation before making isoform claims (standard IHC practice). Report the observed nuclear staining pattern rather than assigning it to a phosphorylation state (standard IHC interpretation).
How can IF help examine an ambiguous PMS2 IHC pattern?
Use IF as a separate localisation check, with a nuclear counterstain and a validated marker for the expected cell type in the specimen (standard IF practice; HPA tissue IHC). For example, HPA reports high PMS2 staining in Purkinje cells and spermatogonia, so a matching cell-type marker can help identify the cells being assessed (HPA tissue IHC). Select fluorophores after inspecting tissue autofluorescence and keep channels spectrally separated for multiplex imaging (standard IF practice). PMS2 has no transmembrane segment and is mainly nucleoplasmic, so permeabilisation should permit antibody access to the nucleus (UniProt P54278 topology; HPA subcellular). Optimise IF conditions independently; the selected M01028-1 caption documents paraffin-section IHC, not IF performance or fixation (selected IHC caption: M01028-1).
What should I check when PMS2 IHC shows diffuse brown background?
First compare the section with a no-primary control processed through the same detection and DAB steps to identify signal unrelated to the primary antibody (standard chromogenic IHC practice). Block endogenous peroxidase before enzyme-based detection, and assess whether the chosen block and washes reduce diffuse color without obscuring nuclear detail (standard chromogenic IHC practice). Reduce overly strong primary-antibody or detection conditions in a controlled titration, because the supplied M01028-1 caption gives no working dilution (selected IHC caption: M01028-1; standard IHC practice). Examine tissue edges, folds, and damaged regions separately from intact fields, where reagent pooling can mislead scoring (standard IHC practice). Accept a PMS2 result on well-preserved nuclear staining, consistent with its supported nucleoplasmic location (HPA subcellular).
How should I quantify PMS2 nuclear staining across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define eligible cells and regions before scoring, then measure the percentage of nuclei with interpretable chromogenic staining in each region (standard IHC scoring practice; UniProt P54278: nucleus). An H-score combines staining intensity categories 0–3 with the percentage at each intensity, yielding a 0–300 score (standard IHC scoring practice). Report the positive-nucleus percentage alongside the H-score so a small intensely stained group remains distinguishable from broad weak staining (standard IHC scoring practice). Normalise positive-cell counts to all eligible nuclei, or report positive nuclear density per mm² of evaluable tissue (standard IHC scoring practice). Exclude folds, necrosis, and edge artefacts consistently, and keep retrieval and imaging settings matched across comparisons (standard IHC practice).
How can I distinguish genuine PMS2 loss from staining artefact?
Look for nuclear staining in intact, expected cells before calling a section positive: PMS2 is nuclear, and HPA describes nuclear expression in most tissues (UniProt P54278; HPA tissue IHC). HPA reports high staining in Purkinje cells and spermatogonia, while adipocytes are listed as not detected; assess the specific cells present rather than assigning one result to an entire tissue (HPA tissue IHC). A negative region is difficult to interpret if nearby expected internal positive nuclei also fail to stain (standard IHC interpretation). Exclude necrotic areas, section edges, and diffuse cytoplasmic deposits from a nuclear loss call (standard IHC practice; HPA subcellular). Check the no-primary control for endogenous enzyme or detection background before attributing residual brown color to PMS2 (standard chromogenic IHC practice).
Boster reagents
Best PMS2 / Mismatch repair endonuclease PMS2 IHC Antibodies
Human-reactive anti-PMS2 antibodies have IHC images from tonsil and rectal carcinoma; M01028-1 also has an IF image (catalog: reactivity and 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 an IHC image of paraffin-embedded human tonsil and an IF image with no sample identified (catalog: M01028-1 applications and image captions). M01028-3 lists human IHC and IF applications, with an IHC image of human rectal carcinoma and no IF image (catalog: M01028-3 applications and image captions).
Which to pick: For paraffin-section IHC, choose M01028-1: its IHC caption identifies paraffin-embedded human tonsil but reports no fixative (catalog: M01028-1 IHC image caption). For IF/ICC, choose M01028-1 because it lists both applications and has an IF image; M01028-3 lists IF but not ICC (catalog: applications and IF image captions). Both are human-reactive rabbit monoclonals, so neither has documented cross-species coverage; M01028-3’s IHC caption identifies human rectal carcinoma but reports neither processing nor fixative (catalog: host, reactivity, and M01028-3 IHC image caption).
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 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 sections (standard IHC practice; not target-specific); Caveat: MLH1 loss may reduce PMS2 staining (UniProt); Isoform / epitope: 4 isoforms; check epitope coverage (UniProt); Regulation: MLH1 binding stabilizes PMS2 (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. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PMS2/immunohistochemistry-ihc-guide.