This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
SNRPD3 / Small nuclear ribonucleoprotein Sm D3 · IHC design guide
Design Immunohistochemistry for SNRPD3
Plan SNRPD3 paraffin-section IHC around widespread nuclear staining (HPA tissue IHC), using breast glandular cells or bronchial respiratory epithelial cells as high-staining controls (HPA tissue IHC). The catalog antibody's IHC dilution is 2–5 μg/ml (datasheet: A09533-1); score nuclear staining with consistent fixation and appropriate controls (standard IHC practice).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SNRPD3 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 (HPA tissue IHC) | |
| Staining pattern | Widespread nuclear staining across tissue cell types (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A09533-1) | |
| Positive control | Breast+4 more · see all | |
| Negative control | None in HPA (detected in all 44 tissues); use no-primary + isotype controls |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections (standard IHC practice; not target-specific) | |
| Caveat | Broad expression limits negative-tissue controls (HPA tissue IHC) | |
| Regulation | Low tissue specificity (HPA tissue RNA) | |
| Isoform / epitope | 2 isoforms; epitope coverage is unknown (UniProt) |
Section 1
Recommended SNRPD3 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by a published SNRPD3 chromogenic IHC protocol for esophageal squamous cell cancer tissue microarrays (PMC9949073).
| Sample | Paraffin-embedded mouse brain tissue; fixative not specified (datasheet A09533-1) |
| Fixation | Image fixative and duration unreported (datasheet A09533-1); 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 A09533-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A09533-1) |
| Primary antibody | Rabbit anti-SNRPD3, 2-5 μg/ml (datasheet A09533-1) |
| Primary incubation | Overnight at 4 °C (datasheet A09533-1) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A09533-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SNRPD3-positive staining in glandular cells of breast (HPA tissue IHC: High). HPA tissue profile: Ubiquitous nuclear expression. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval (datasheet A09533-1); the published protocol used a basic pH 9.0 buffer (PMC9949073).
Section 2
What Is the Expected SNRPD3 Staining Pattern?
SNRPD3 should show widespread nuclear staining in IHC, including strong staining in several glandular and respiratory epithelial cell populations (HPA tissue IHC: ubiquitous nuclear expression; High in listed populations). Cytosolic staining is biologically plausible because snRNP assembly begins in the cytosol before nuclear transport (UniProt P62318: subcellular location). SNRPD3 has no transmembrane segment (UniProt P62318: topology). HPA rates the tissue IHC pattern Supported, with medium consistency between staining and RNA expression (HPA tissue IHC: reliability).
| Clear nuclear signal in breast glandular cells, bronchial respiratory epithelial cells, or pancreatic exocrine glandular cells (HPA tissue IHC: High in each). | This fits the reported widespread nuclear pattern (HPA tissue IHC: ubiquitous nuclear expression). Compare nuclei with adjacent cells and background on the same section; intensity alone does not establish antibody specificity (general IHC practice). |
| Predominantly cytoplasmic staining with little or no nuclear signal in cells expected to stain (HPA tissue IHC: ubiquitous nuclear expression). | Review specificity and detection conditions before calling the pattern positive (general IHC practice). Some cytosolic signal is plausible, especially in IF, but nucleoplasm is the main supported IF location (HPA subcellular ICC-IF: nucleoplasm main; cytosol additional). |
| Strong color in structures outside the expected cellular pattern, such as pigment, debris, or tissue edges (general IHC practice). | Cross-reactivity, endogenous detection activity, or a preparation artefact may explain it (general IHC practice). SNRPD3 expression is widespread, so staining in an unlisted cell type alone does not prove an off-target result (HPA tissue IHC: ubiquitous nuclear expression). |
| Diffuse color across cells and extracellular spaces obscures nuclear boundaries (general IHC practice). | Interpret the section as high background until controls clarify the signal (general IHC practice). The reported tissue pattern is nuclear; diffuse extracellular color is not evidence of SNRPD3 localization (HPA tissue IHC: ubiquitous nuclear expression). |
| No nuclear signal in a positive reference section containing breast glandular cells or bronchial respiratory epithelial cells (HPA tissue IHC: High in both). | Check that tissue, primary antibody, detection reagents, and counterstain were processed as intended (general IHC practice). HPA's High designation provides a reference expectation, not a guarantee for every specimen or staining run (HPA tissue IHC: High; reliability Supported). |
💡Expected SNRPD3 appearanceCall the IHC result consistent with SNRPD3 when nuclear staining is readily visible in the listed High populations (HPA tissue IHC: ubiquitous nuclear expression; High in listed populations); treat diffuse extracellular color or predominantly extranuclear staining without nuclear signal as a result needing review (general IHC practice; HPA subcellular ICC-IF: nucleoplasm main).
| Tissue and cell population (HPA tissue IHC). | HPA reports High staining in breast and fallopian tube glandular cells, bronchial respiratory epithelial cells, and pancreatic exocrine glandular cells; it reports Low staining in oral squamous epithelium and salivary glandular cells (HPA tissue IHC: listed levels). Use the named cell population when comparing sections. |
| Strength of the tissue evidence (HPA tissue IHC: Supported). | The nuclear profile has medium consistency between antibody staining and RNA expression (HPA tissue IHC: reliability description). HPA lists no negative tissue in this payload, so the Low populations are weaker comparators, not established negative controls (HPA tissue IHC: Low; negative list empty). |
| Nuclear and cytosolic distribution (UniProt P62318; HPA subcellular ICC-IF). | UniProt places SNRPD3 in nucleus and cytosol and describes cytosolic snRNP assembly before nuclear transport (UniProt P62318: subcellular location). IF shows nucleoplasm as the main supported location, with nuclear bodies and cytosol additionally supported (HPA subcellular ICC-IF: locations). |
| Available antibody validation (HPA antibodies: HPA001170). | HPA labels HPA001170 Supported for both IHC and ICC (HPA antibodies: HPA001170 validation). This supports using its reported pattern as a comparison; it does not by itself establish that another antibody has the same specificity (general IHC practice). |
| IF/ICC interpretation (HPA subcellular ICC-IF). | Q: Should IF show only nuclei? A: Expect mainly nucleoplasm, while nuclear bodies and cytosol can also be seen (HPA subcellular ICC-IF: supported locations). The IF observations guide compartment interpretation here; this IHC section provides no IF protocol option. |
| Situation | Likely cause | Next action |
|---|---|---|
| The positive reference section is blank (HPA tissue IHC: High in breast glandular cells and bronchial respiratory epithelial cells). | A staining run or detection failure is possible (general IHC practice); HPA does not establish a target-specific fixation effect (HPA tissue IHC: source scope). | Verify the reference cell population and inspect run controls, primary antibody handling, and detection reagents (general IHC practice). Do not infer fixation sensitivity from the blank result alone. |
| Staining is strongest in cytoplasm and nuclei are faint (HPA tissue IHC: ubiquitous nuclear expression). | The distribution may reflect background or a specificity problem, although cytosolic SNRPD3 is plausible (general IHC practice; UniProt P62318: subcellular location). | Compare with a reported High tissue population and check the no-primary control; assess whether discrete nuclear signal remains (HPA tissue IHC: High in listed populations; general IHC practice). |
| Color appears broadly in extracellular spaces or at section edges (general IHC practice). | Nonspecific staining or detection background may obscure cellular localization (general IHC practice). | Inspect the no-primary control, blocking, washes, and detection steps, then score only interpretable cells (general IHC practice). HPA's reported pattern is widespread nuclear expression (HPA tissue IHC: profile). |
| Unexpected cells stain strongly while expected nuclei are weak (HPA tissue IHC: ubiquitous nuclear expression). | Cross-reactivity or endogenous detection activity is possible, but HPA provides no negative tissue here (general IHC practice; HPA tissue IHC: negative list empty). | Identify the stained cell type, check no-primary and detection controls, and compare a named High population before assigning the signal to SNRPD3 (general IHC practice; HPA tissue IHC: listed High populations). |
| Oral squamous epithelium looks weaker than breast glandular cells (HPA tissue IHC: Low and High, respectively). | This difference agrees with the reported staining levels and need not indicate a failed run (HPA tissue IHC: listed levels). | Score each named cell population against its reported level and the run controls (HPA tissue IHC: listed levels; general IHC practice). Do not use the Low population as a proven negative control (HPA tissue IHC: negative list empty). |
| IF shows nuclear bodies or cytosol alongside nucleoplasm (HPA subcellular ICC-IF: supported locations). | These are reported additional locations; nucleoplasm remains the main supported IF location (HPA subcellular ICC-IF: locations). | Interpret IF compartment staining using its own guide and controls (general IF practice). For this IHC section, compare chromogenic tissue staining with HPA's widespread nuclear profile (HPA tissue IHC: profile). |
Experiment evidence
IHC & IF images showing SNRPD3 staining
A09533-1 · IHCIHC analysis of Sm-D3/SNRPD3 using anti-Sm-D3/SNRPD3 antibody (A09533-1). Sm-D3/SNRPD3 was detected in a paraffin-embedded section of mouse
A09533-1 · IHCIHC analysis of Sm-D3/SNRPD3 using anti-Sm-D3/SNRPD3 antibody (A09533-1). Sm-D3/SNRPD3 was detected in a paraffin-embedded section of rat br
A09533-1 · IFIF analysis of Sm-D3/SNRPD3 using anti-Sm-D3/SNRPD3 antibody (A09533-1). Sm-D3/SNRPD3 was detected in a paraffin-embedded section of human b
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000100028-SNRPD3/tissue/cerebral+cortex#imid_469730
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000100028-SNRPD3/tissue/colon#imid_469664
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000100028-SNRPD3/tissue/liver#imid_469649
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000100028-SNRPD3/tissue/kidney#imid_469650
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA001170; green = SNRPD3, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA001170; green = SNRPD3, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SNRPD3 IHC & IF
🧪Run breast first and require staining in glandular cells (HPA: High in breast glandular cells). HPA detects SNRPD3 in all 44 scored tissues, so there is no validated negative tissue; use no-primary and isotype controls, and treat unstained cells on the breast slide as possible internal background references, not established target-negative cells (HPA: no negative rows; standard IHC practice).
Positive control tissue: Breast (Glandular cells, HPA High)
Negative control tissue: None in HPA: SNRPD3 is detected in all 44 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 SNRPD3 in A-431, U-251MG, U2OS, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Run a no-primary, secondary-only slide and a rabbit IgG isotype control matched to the catalog antibody’s host and Ig class, alongside SNRPD3-knockout material if available (selected-SKU caption: rabbit primary; standard IHC practice). Check the breast section for endogenous peroxidase activity before interpreting DAB staining (standard chromogenic IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected-SKU paraffin-section caption does not state the fixative (selected-SKU caption: fixative unreported). The caption uses heat retrieval in EDTA at pH 8.0, but does not establish that retrieval is required for every specimen; whether frozen sections or IF are easier is unreported (selected-SKU caption: EDTA retrieval; HPA: ICC-IF localization data). For IF/ICC, nucleoplasmic signal with possible nuclear-body and cytosolic signal is supported, while breast DAB interpretation should account for endogenous peroxidase background (HPA: supported subcellular locations; standard IHC practice).
HPA tissue IHC evidence for SNRPD3
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — 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 |
|---|---|---|---|---|
| Breast | Glandular cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebral cortex | Neuropil | High | Protein (IHC) | HPA → |
| Epididymis | Glandular cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: SNRPD3 is detected in all 44 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced SNRPD3 IHC Tips
Troubleshoot chromogenic SNRPD3 IHC in paraffin sections using the catalog antibody’s tissue staining conditions and expected cellular localisation.
How should I adjust retrieval when SNRPD3 nuclear staining is weak?
Start with heat-mediated retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A09533-1). The catalog antibody’s mouse brain image used that retrieval, followed by 2 μg/ml primary antibody overnight at 4°C (datasheet A09533-1). If staining remains weak, check retrieval heating and section adhesion before cautiously comparing another buffer; keep detection and exposure conditions matched across sections (general IHC practice). Judge improvement by clearer nuclear staining with limited diffuse background, using a consistently processed comparison section because SNRPD3 is mainly nucleoplasmic (HPA subcellular: nucleoplasm supported).
Can fixation explain weak SNRPD3 staining in paraffin sections?
The selected paraffin-section caption does not state a fixative, so target-specific fixation sensitivity is unknown (datasheet A09533-1: fixative not stated). Record the fixative, fixation duration, and tissue processing history for each sample, then compare sections processed together before attributing a difference to SNRPD3 abundance (general IHC practice). Keep retrieval at EDTA pH 8.0 and the primary incubation at 2 μg/ml overnight at 4°C while investigating fixation (datasheet A09533-1). Assess nuclear morphology alongside staining; damaged or unevenly preserved sections make compartment-level comparisons unreliable (general IHC practice; HPA subcellular: mainly nucleoplasmic).
Is cytoplasmic SNRPD3 staining plausible in chromogenic IHC?
SNRPD3 is mainly nucleoplasmic, with additional nuclear-body and cytosolic localisation reported, so nuclear staining should anchor interpretation (HPA subcellular: supported locations). Cytosolic SNRPD3 is biologically plausible because SMN-mediated snRNP assembly precedes transport to the nucleus (UniProt P62318: subcellular location). Compare cytoplasmic signal against nuclear signal within intact cells, and inspect adjacent sections for diffuse DAB deposition or tissue-edge staining (general IHC practice). The protein has no transmembrane segment, so a crisp cell-surface outline alone would warrant scrutiny rather than a membrane-localisation claim (UniProt P62318: topology).
Could isoforms or epitope masking change the IHC pattern?
SNRPD3 has 2 annotated isoforms and an Sm domain spanning residues 5–77, but the supplied caption does not identify this antibody’s epitope (UniProt P62318: isoforms and domains; datasheet A09533-1). Avoid assigning staining differences to a particular isoform without epitope mapping or independent isoform-specific evidence (general IHC interpretation). Its C-terminus interacts directly with SMN1, while the record also notes a modified residue at position 2; neither fact establishes masking in fixed sections (UniProt P62318: subunit and modified residues). If signal changes with retrieval, compare nuclear pattern and tissue integrity before proposing an epitope-based mechanism (general IHC practice).
How can IF help check a disputed SNRPD3 IHC pattern?
Use IF/ICC as a localisation cross-check when chromogenic IHC leaves nuclear and cytoplasmic signal hard to separate; SNRPD3 is mainly nucleoplasmic with additional cytosolic signal (HPA subcellular: supported locations). In a multiplex experiment, pair SNRPD3 with a marker for the cell population being evaluated and choose fluorophores outside prominent tissue autofluorescence channels (general IF practice). Permeabilise cells sufficiently to access intracellular nuclear and cytosolic epitopes, then compare matched controls for nonspecific fluorescence (UniProt P62318: no transmembrane segment; general IF practice). Treat IF findings as supporting evidence for the paraffin-section interpretation, with assay conditions documented separately (general IHC/IF practice).
What should I check when DAB obscures SNRPD3 nuclei?
First inspect a section without primary antibody to distinguish detection-system background from specific nuclear staining (general chromogenic IHC practice; HPA subcellular: mainly nucleoplasmic). The catalog image used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, and a peroxidase-linked secondary for 30 minutes at 37°C (datasheet A09533-1). Peroxidase blocking and controlled DAB development are general workflow checks when diffuse brown signal obscures nuclei (general chromogenic IHC practice). Compare background across the section, including edges and damaged areas, before increasing primary concentration or interpreting broad cytoplasmic colour as SNRPD3 (general IHC practice; HPA subcellular: additional cytosolic location).
How should I score SNRPD3 staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the analysed cell population and score nuclear staining separately from cytoplasmic staining, because nucleoplasm is the main supported location (HPA subcellular: nucleoplasm and cytosol supported). For chromogenic sections, report either an H-score combining intensity and percentage of positive cells, or the percentage of positive nuclei within a prespecified compartment (general IHC scoring practice). Normalise counts to the number of intact cells assessed, or report positive-cell density per mm² of viable analysed tissue when cell counts are impractical (general IHC quantification practice). Hold retrieval, DAB development, image acquisition, and scoring thresholds constant across groups (general IHC practice).
How do I distinguish true SNRPD3 signal from artefact?
A convincing pattern includes staining in intact nuclei, consistent with ubiquitous nuclear expression and mainly nucleoplasmic localisation (HPA tissue IHC: ubiquitous nuclear expression; HPA subcellular: nucleoplasm supported). Cytosolic signal can occur, but an isolated membrane outline is inconsistent with the annotated absence of a transmembrane segment (HPA subcellular: cytosol supported; UniProt P62318: topology). Check whether apparent positives cluster at tissue edges or in necrotic regions, and compare a no-primary control for endogenous enzyme or detection background (general chromogenic IHC practice). Use appropriate cell identification before treating differences among cell types as biological; reported tissue staining varies by cell population (HPA tissue IHC: positive and low examples).
Boster reagents
Best SNRPD3 / Small nuclear ribonucleoprotein Sm D3 IHC Antibodies
A09533-1 has IHC images from paraffin sections of mouse and rat brain, human breast cancer and glioblastoma, plus an IF image from human breast cancer (catalog image captions).
Real IHC data
Anti-Sm-D3/SNRPD3 Antibody ®
Cat # A09533-1
A09533-1 has IHC images from paraffin sections of mouse and rat brain, human breast cancer and glioblastoma (catalog IHC image captions). A09533-1 also has an IF image from a paraffin section of human breast cancer; its listed reactivity is human, mouse and rat (catalog IF image caption; catalog reactivity).
Which to pick: For tissue IHC, choose A09533-1: it is a rabbit antibody listed for IHC, with paraffin-section images using EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody (catalog applications; catalog IHC image captions). For IF, A09533-1 has an image from a human breast cancer paraffin section at 5 μg/ml; ICC validation is not reported (catalog IF image caption; catalog applications). For cross-species IHC, A09533-1 lists human, mouse and rat reactivity and has paraffin-section images from all three species; the captions do not report the fixative (catalog reactivity; catalog IHC image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P62318 (SMD3_HUMAN, Small nuclear ribonucleoprotein Sm D3).
- Human Protein Atlas. SNRPD3 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. SNRPD3 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the nuclear bodies and cytosol..
- Human Protein Atlas. SNRPD3 antibody validation summary (1 antibodies).
- Tumor Niche Network-Defined Subtypes Predict Immunotherapy Response of Esophageal Squamous Cell Cancer. bioRxiv : the preprint server for biology 2023 — PMC9949073.
- Identification of Three Genes Associated with Metastasis in Melanoma and Construction of a Predictive Model: A Multiracial Identification. Journal of oncology 2022 — PMC9148232.
- PubMed PMID:7527560 — UniProt-cited evidence.
- PubMed PMID:15461802 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SNRPD3 (Small nuclear ribonucleoprotein Sm D3). Expected localisation Nuclear staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A09533-1). Validated IHC antibody: A09533-1 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Breast (Glandular cells); negative None in HPA (detected in all 44 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded mouse brain tissue; fixative not specified (datasheet A09533-1); 2. Fixation: Image fixative and duration unreported (datasheet A09533-1); 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 A09533-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A09533-1); 8. Primary antibody: Rabbit anti-SNRPD3, 2-5 μg/ml (datasheet A09533-1); 9. Primary incubation: Overnight at 4 °C (datasheet A09533-1). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Broad expression limits negative-tissue controls (HPA tissue IHC); Isoform / epitope: 2 isoforms; epitope coverage is unknown (UniProt); Regulation: Low tissue specificity (HPA tissue RNA). Evidence: UniProt P62318, HPA tissue IHC · Supported, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A09533-1, PMC9949073. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SNRPD3/immunohistochemistry-ihc-guide.