This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
POLD1 / DNA polymerase delta catalytic subunit · IHC design guide
Design Immunohistochemistry for POLD1
Use the general nuclear tissue pattern to assess POLD1 staining in paraffin sections (HPA tissue IHC). This guide covers fixation consistency, chromogenic detection and nuclear scoring, using 2 μg/ml as a catalog antibody starting concentration (datasheet: M03720).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
POLD1 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 | General nuclear staining (HPA tissue IHC) | |
| Staining pattern | Nuclear staining; high in colon glandular cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet M03720) | |
| Positive control | Appendix+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 paraffin sections (standard IHC practice; not target-specific) | |
| Caveat | Low staining in cholangiocytes and adipocytes (HPA tissue IHC) | |
| Regulation | Abundance regulation not specified (UniProt) | |
| Isoform / epitope | One 1–1107 chain; no isoforms annotated (UniProt) |
Section 1
Recommended POLD1 IHC & IF Protocols
The catalog antibody uses an EDTA pH 8.0 retrieval protocol (datasheet: M03720). Three published POLD1 IHC protocols provide additional tissue and detection details (PMC7583138; PMC6907229; PMC10095303).
| Sample | Paraffin-embedded human colon cancer tissue; fixative not specified (datasheet M03720) |
| Fixation | Image fixative and duration unreported (datasheet M03720); 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 M03720); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet M03720) |
| Primary antibody | Rabbit monoclonal (clone 21P14) anti-POLD1, 1:50 recommended; image 2 μg/ml (datasheet M03720) |
| Primary incubation | Overnight at 4 °C (datasheet M03720) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet M03720) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | POLD1-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: General nuclear expression. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet: M03720); consider pH 9.0 pressure retrieval when adapting the published thyroid or endometrial protocols (PMC7583138; PMC6907229).
Section 2
What Is the Expected POLD1 Staining Pattern?
POLD1 is a nuclear DNA polymerase with no transmembrane segment (UniProt P28340: nucleus; topology). In paraffin-section IHC, expect staining mainly in nuclei across multiple cell types (HPA: general nuclear expression; low tissue specificity). HPA reports high staining in appendix and colon glandular cells, cervical squamous cells, and kidney tubular cells (HPA: tissue IHC). Its tissue IHC profile is supported by consistency between antibody staining and RNA expression (HPA: reliability Supported).
| Nuclear staining in glandular cells of appendix or colon, squamous epithelial cells of cervix, or kidney tubular cells. | This matches the reported compartment and high-staining cell populations (HPA: general nuclear expression; High in these cells). Compare nuclei with adjacent tissue structures on the same section; high is HPA's reported category, not a required score for every specimen. |
| Predominantly membranous staining, or cytoplasmic staining that obscures the nuclei. | This conflicts with the expected IHC pattern (HPA: general nuclear expression; UniProt P28340: nucleus, no transmembrane segment). Review localisation before scoring it as POLD1. HPA separately reports uncertain additional cytosolic localisation by ICC-IF, so a minor cytosolic signal alone is inconclusive (HPA: subcellular). |
| Strong staining in an unexpected cell population while the reported positive cells lack nuclear signal. | Consider antibody cross-reactivity or endogenous chromogenic detection activity (standard IHC practice). Check the staining against tissue morphology and the reported cell-level pattern; HPA's low tissue specificity does not make every cell type an equally strong positive (HPA: tissue IHC). |
| Diffuse colour across nuclei, cytoplasm, and tissue spaces, with little distinction between cells. | Treat this as background until controls support a cellular pattern (standard IHC practice). Broad POLD1 expression does not explain colour in tissue spaces (HPA: low tissue specificity; general nuclear expression). Reassess blocking, washes, and detection controls before interpreting intensity. |
| No nuclear staining in an appendix or colon section with identifiable glandular cells. | This misses a reported high-staining population (HPA: High in appendix and colon glandular cells). Check the section and assay controls first (standard IHC practice). A single negative result cannot establish absence of POLD1, especially without a working positive control. |
💡Expected POLD1 appearanceCall a convincing positive result when identifiable cells show predominantly nuclear chromogenic signal, especially reported high-staining glandular, squamous, or tubular populations (HPA: tissue IHC); strong membrane staining or diffuse colour without nuclear definition argues against the expected pattern (HPA: general nuclear expression; UniProt P28340: topology).
| Cell population and comparator tissue | HPA reports High staining in appendix, colon, duodenum, and fallopian tube glandular cells; cervical and esophageal squamous cells; cerebellar Purkinje cells; and kidney tubular cells (HPA: tissue IHC). Liver cholangiocytes and adipocytes are Low, so they are weaker comparators, not established negatives (HPA: tissue IHC). |
| Nuclear localisation and replication context | POLD1 is nuclear and colocalises with PCNA and POLD3 at S-phase replication sites (UniProt P28340: subcellular). That supports nuclear interpretation but does not require visible replication foci in routine chromogenic sections; HPA describes the tissue-level appearance as general nuclear expression (HPA: tissue IHC). |
| Antibody evidence | HPA lists HPA046524 and CAB004375 as IHC Supported; HPA046524 is also ICC Supported (HPA: antibodies). These statuses support use of the observed patterns as comparators, but they do not validate an unspecified catalog antibody, dilution, or retrieval condition. |
| Topology and processing | UniProt reports no transmembrane segment, signal peptide, propeptide, or alternative isoforms, and describes one chain spanning residues 1–1107 (UniProt P28340: topology; processing; isoforms). These annotations give no basis to expect a membrane-restricted or secreted IHC pattern; they do not identify an antibody epitope. |
| IF/ICC Q&A | Q: Should IF/ICC show the same compartment? A: Predominantly nucleoplasmic signal is supported; additional cytosolic localisation is uncertain (HPA: subcellular ICC-IF). Treat that as a localisation cross-check, not an IHC protocol option. HPA lists ICC images for A-431, HEK293, U2OS, and NIH 3T3 (HPA: subcellular). |
| Situation | Likely cause | Next action |
|---|---|---|
| Reported high-staining cells show no nuclear signal. | The assay may have failed, or section conditions may be unsuitable; the slide alone cannot distinguish these possibilities (standard IHC practice). | Confirm tissue identity and cell preservation, then inspect positive and detection controls; review the antibody's IHC validation and the chosen retrieval and dilution settings (standard IHC practice; HPA: High in the selected cells). |
| Signal is mainly at cell borders or membranes. | This differs from the nuclear pattern and lacks support from POLD1 topology (HPA: general nuclear expression; UniProt P28340: no transmembrane segment). | Check whether nuclear counterstain and cell boundaries are being read correctly; compare with a known positive tissue and a detection control before attributing the border signal to POLD1 (standard IHC practice). |
| Unexpected cells stain strongly while expected nuclei are faint. | Cross-reactivity or endogenous detection activity is possible; HPA's tissue profile does not establish the identity of this signal (standard IHC practice; HPA: tissue IHC). | Check staining without primary antibody for detection background, and compare the suspicious cells with reported high-staining populations on a positive section (standard IHC practice; HPA: tissue IHC). |
| Brown colour is diffuse and obscures nuclear boundaries. | Background from blocking, washing, or detection can prevent localisation assessment (standard IHC practice). | Review blocking and wash steps, then assess a detection control and the nuclear counterstain. Score POLD1 only where cellular nuclear signal remains distinguishable (standard IHC practice; HPA: general nuclear expression). |
| Low signal in liver cholangiocytes or adipocytes is called assay failure. | Both populations are reported Low rather than negative (HPA: tissue IHC). Their weak staining is a poor standalone test of assay performance. | Use a reported High population, such as colon glandular cells or kidney tubular cells, as a positive comparator and assess its nuclear pattern (HPA: tissue IHC; general nuclear expression). |
| IF/ICC shows nucleoplasmic signal plus some cytosolic fluorescence. | HPA supports nucleoplasmic localisation but marks additional cytosolic localisation uncertain (HPA: subcellular ICC-IF). Fluorescence alone does not settle whether that component is specific. | Record the nucleoplasmic pattern as the supported localisation and interpret the cytosolic component cautiously against controls (HPA: subcellular ICC-IF; standard IF practice). Keep IF/ICC protocol decisions in its separate guide. |
Experiment evidence
IHC & IF images showing POLD1 staining
M03720 · IHCIHC analysis of POLD1 using anti-POLD1 antibody (M03720) . POLD1 was detected in a paraffin-embedded section of human colon cancer tissue. H
M03720 · IHCIHC analysis of POLD1 using anti-POLD1 antibody (M03720) . POLD1 was detected in a paraffin-embedded section of human lung adenocarcinoma ti
A03720-2 · IHCIHC analysis of POLD1 using anti-POLD1 antibody (A03720-2). POLD1 was detected in a paraffin-embedded section of human bladder cancer tissue
A03720-2 · IFIF analysis of POLD1 using anti-POLD1 antibody (A03720-2) and anti-Beta Tubulin antibody (M01857-3). POLD1 was detected in an immunocytochem
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000062822-POLD1/tissue/cerebral+cortex#imid_1362324
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000062822-POLD1/tissue/colon#imid_1362258
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000062822-POLD1/tissue/liver#imid_1362259
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000062822-POLD1/tissue/kidney#imid_1362268
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA046524; green = POLD1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA046524; green = POLD1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for POLD1 IHC & IF
🧪Run colon first and look for POLD1 staining in glandular cells (HPA: High in colon glandular cells). HPA detects POLD1 in all 45 scored tissues, so there is no validated negative tissue; use no-primary and isotype controls, and treat any cells on the positive slide without nuclear signal as background references rather than proven POLD1-negative cells (HPA: no negative tissue rows; UniProt P28340: nucleus).
Positive control tissue: Appendix (Glandular cells, HPA High)
Negative control tissue: None in HPA: POLD1 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 POLD1 in A-431, HEK293, U2OS, NIH 3T3, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control, a matched nonimmune rabbit IgG isotype control, and POLD1-knockout material as a biological negative when available (selected M03720 caption: rabbit anti-POLD1; standard IHC practice). For chromogenic colon sections, block endogenous peroxidase before HRP/DAB detection (selected M03720 caption: HRP/DAB; standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected M03720 paraffin-section caption does not state the fixative (selected M03720 caption). Heat-mediated retrieval in EDTA at pH 8.0 is a documented starting condition, but its necessity has not been established by the supplied evidence (selected M03720 caption). The supplied evidence does not establish that frozen sections or IF are easier; for IF, assess nucleoplasmic signal against the less certain cytosolic signal, while for colon IHC account for endogenous peroxidase background (HPA: nucleoplasm supported, cytosol uncertain; standard IHC practice).
HPA tissue IHC evidence for POLD1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — High consistency between antibody staining and RNA expression data.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Cerebellum | Purkinje cells | High | Protein (IHC) | HPA → |
| Cervix | Squamous epithelial cells | High | Protein (IHC) | HPA → |
| Colon | Glandular cells | High | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: POLD1 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced POLD1 IHC Tips
Troubleshoot POLD1 staining in paraffin sections by checking retrieval, nuclear localisation and controls before comparing chromogenic signal across samples.
Which retrieval conditions should I try first for weak POLD1 staining?
Start with heat mediated retrieval in EDTA at pH 8.0 (datasheet M03720). The catalog antibody detected POLD1 in a paraffin section after this retrieval, followed by 2 μg/ml primary antibody overnight at 4°C (datasheet M03720). If nuclei remain weak, adjust heating time on matched sections while keeping the antibody concentration and detection steps constant; the caption gives no retrieval duration (datasheet M03720; standard IHC practice). Compare signal in glandular cells with nearby low staining tissue, and inspect morphology after each change, because stronger staining accompanied by tissue damage is difficult to interpret (HPA: high in colon glandular cells; standard IHC practice).
Could fixation explain variable POLD1 nuclear staining between paraffin blocks?
Target specific fixation sensitivity is unknown: the selected paraffin tissue caption does not state a fixative (datasheet M03720). Record each block’s fixative and fixation interval, then compare blocks processed under the same conditions before attributing weaker nuclei to biology (standard IHC practice). Keep EDTA retrieval at pH 8.0 and primary antibody at 2 μg/ml constant during that comparison (datasheet M03720). Include a previously staining section in each run and check whether weak signal tracks processing history, tissue preservation or the detection run (standard IHC practice). Nuclear localisation and the annotated modification at residue 19 do not establish a fixation effect (UniProt P28340).
How should I assess cytoplasmic staining when scoring POLD1 IHC?
Score nuclear staining first, because POLD1 is annotated as nuclear and its main supported location is the nucleoplasm (UniProt P28340; HPA: nucleoplasm supported). HPA also reports cytosol as an uncertain additional location, so record reproducible cytoplasmic signal separately instead of adding it to a nuclear score (HPA: cytosol uncertain). POLD1 can colocalise with PCNA at S phase replication sites, but a chromogenic section cannot establish that colocalisation without a matched marker assay (UniProt P28340; standard IHC practice). Compare intact cells with their neighbours, counterstain sufficiently to define nuclei, and reassess diffuse staining that crosses tissue boundaries or persists in a no primary control (standard IHC practice).
Can isoforms or epitope accessibility account for uneven POLD1 staining?
The supplied record lists 0 isoforms and one chain spanning residues 1–1107, so an isoform specific staining explanation lacks support here (UniProt P28340). It lists no transmembrane segment and an omega N methylarginine at residue 19, but the antibody epitope is not specified (UniProt P28340; datasheet M03720). Do not infer that this modification blocks antibody binding without epitope mapping or direct testing (UniProt P28340; standard IHC practice). Check whether EDTA retrieval at pH 8.0 restores nuclear signal across matched sections, and retain a consistently staining section as a processing control (datasheet M03720; standard IHC practice).
How can I check a POLD1 IHC pattern using multiplex IF?
Use IF as a separate localisation check, pairing POLD1 with a glandular cell marker when examining colon tissue, where HPA reports high glandular cell staining (HPA: colon glandular cells high; standard IF practice). Choose a red or far red POLD1 fluorophore after inspecting tissue autofluorescence, and acquire single stain controls to assess spectral bleed through (standard IF practice). Because POLD1 is mainly nucleoplasmic and has no transmembrane segment, optimise permeabilisation for access to the nuclear epitope after fixation; the antibody epitope is unspecified (HPA: nucleoplasm supported; UniProt P28340; datasheet M03720; standard IF practice). Score overlap within counterstained nuclei, and treat the paraffin IHC caption as IHC evidence rather than an IF fixation or dilution protocol (datasheet M03720; standard IF practice).
What should I check when POLD1 DAB staining is diffuse?
First compare a no primary control with the stained section and identify whether colour persists in tissue compartments or at section edges (standard IHC practice). Block endogenous peroxidase and review serum blocking and washes before increasing antibody dilution; these are general chromogenic workflow checks (standard IHC practice). The reported example used 10% goat serum, 2 μg/ml primary overnight at 4°C, and a peroxidase conjugated secondary for 30 minutes at 37°C (datasheet M03720). Judge any adjustment against preserved nuclear contrast, since the supported tissue pattern is generally nuclear and HPA reports low staining in adipocytes and cholangiocytes (HPA: general nuclear expression; HPA: adipocytes and cholangiocytes low).
How should I quantify POLD1 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and score only evaluable nuclei within matched tissue regions, recording cytoplasmic staining separately (HPA: nucleoplasm supported; standard IHC practice). For an H score, assign nuclear intensity 0–3, multiply each intensity by its percentage of cells, and sum to a 0–300 score (standard IHC practice). Also report the percentage of positive nuclei and the number of evaluable cells, with identical thresholds and imaging conditions across cases (standard IHC practice). Normalise counts to the relevant cell population or sampled tissue area, such as positive nuclei per mm², and exclude necrosis and section edges by a prespecified rule (standard IHC practice).
How can I distinguish credible POLD1 staining from section artefacts?
Credible signal should concentrate in intact nuclei, consistent with POLD1’s nuclear annotation and HPA’s supported nucleoplasmic localisation (UniProt P28340; HPA: nucleoplasm supported). Compare expected cell populations: HPA reports high staining in colon glandular cells but low staining in adipocytes and cholangiocytes (HPA: colon glandular cells high; HPA: adipocytes and cholangiocytes low). Recheck colour confined to cut edges or necrotic areas, and investigate staining in a no primary control as possible detection background or endogenous enzyme activity (standard IHC practice). The catalog image demonstrates detection in a paraffin section of human colon cancer, but its caption does not state the fixative or establish specificity for every staining pattern (datasheet M03720).
Boster reagents
Best POLD1 / DNA polymerase delta catalytic subunit IHC Antibodies
POLD1 antibodies have human paraffin-section IHC images (catalog IHC captions); A03720-2 also has a U2OS cell IF image (catalog IF caption). Both list human, mouse, and rat reactivity (catalog applications/reactivity).
Real IHC data
Anti-POLD1 Rabbit Monoclonal Antibody
Cat # M03720
Real IHC data
Anti-POLD1 Antibody ®
Cat # A03720-2
M03720 has IHC images from human colon cancer, lung adenocarcinoma, ovarian cancer, and tonsil paraffin sections (M03720 IHC captions). A03720-2 has a human bladder cancer paraffin-section IHC image and a U2OS cell IF image (A03720-2 IHC/IF captions).
Which to pick: For tissue IHC, choose M03720 if its broader set of human paraffin-section images is useful; its caption specifies EDTA retrieval at pH 8.0, while the fixative is unreported (M03720 IHC captions). For IF/ICC, choose A03720-2 because it has a U2OS cell IF image; its own IHC caption also supports paraffin-section use with EDTA retrieval at pH 8.0, with fixative unreported (A03720-2 IF/IHC captions). Both list human, mouse, and rat reactivity, but the supplied IHC images show human samples only; M03720 is monoclonal and A03720-2 is polyclonal (catalog applications/reactivity; catalog antibody descriptions; IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P28340 (DPOD1_HUMAN, DNA polymerase delta catalytic subunit).
- Human Protein Atlas. POLD1 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. POLD1 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
- Human Protein Atlas. POLD1 antibody validation summary (2 antibodies).
- Altered immunoexpression of DNA polymerase delta 1 catalytic subunit (POLD1) in colorectal cancer. Contemporary oncology (Poznan, Poland) 2023 — PMC10793622.
- POLE and POLD1 pathogenic variants in the proofreading domain in papillary thyroid cancer. Endocrine connections 2020 — PMC7583138.
- Germline POLE and POLD1 proofreading domain mutations in endometrial carcinoma from Middle Eastern region. Cancer cell international 2019 — PMC6907229.
- POLD1 as a Prognostic Biomarker Correlated with Cell Proliferation and Immune Infiltration in Clear Cell Renal Cell Carcinoma. International journal of molecular sciences 2023 — PMC10095303.
- PubMed PMID:1722322 — UniProt-cited evidence.
- PubMed PMID:1542570 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for POLD1 (DNA polymerase delta catalytic subunit). Expected localisation General nuclear staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet M03720). Validated IHC antibody: M03720 at 1:50 recommended; image 2 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colon cancer tissue; fixative not specified (datasheet M03720); 2. Fixation: Image fixative and duration unreported (datasheet M03720); 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 M03720); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet M03720); 8. Primary antibody: Rabbit monoclonal (clone 21P14) anti-POLD1, 1:50 recommended; image 2 μg/ml (datasheet M03720); 9. Primary incubation: Overnight at 4 °C (datasheet M03720). Watch for: Fixation: Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific); Caveat: Low staining in cholangiocytes and adipocytes (HPA tissue IHC); Isoform / epitope: One 1–1107 chain; no isoforms annotated (UniProt); Regulation: Abundance regulation not specified (UniProt). Evidence: UniProt P28340, HPA tissue IHC · Supported, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet M03720, PMC7583138, PMC6907229. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/POLD1/immunohistochemistry-ihc-guide.