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SNRPA1 / U2 small nuclear ribonucleoprotein A' · IHC design guide
Design Immunohistochemistry for SNRPA1
Plan SNRPA1 staining in paraffin sections using its ubiquitous nuclear tissue pattern as the expected result (HPA tissue IHC). This guide covers fixation consistency, the catalog antibody’s 2–5 μg/ml IHC range (datasheet A10655-1), chromogenic detection, and interpretation of low signal in muscle cells (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SNRPA1 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 | Ubiquitous 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 A10655-1) | |
| Positive control | Adrenal gland+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 paraffin-section fixation consistent between samples. (standard IHC practice; not target-specific) | |
| Caveat | Low signal in cardiomyocytes and skeletal myocytes (HPA tissue IHC) | |
| Regulation | Tissue-specific regulation unannotated (UniProt) | |
| Isoform / epitope | 0 isoforms annotated; chain spans residues 2–255 (UniProt) |
Section 1
Recommended SNRPA1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is paired here with one published lung tissue IHC protocol (PMC10435942: methods).
| Sample | Paraffin-embedded human glioblastoma tissue; fixative not specified (datasheet A10655-1) |
| Fixation | Image fixative and duration unreported (datasheet A10655-1); 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 A10655-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A10655-1) |
| Primary antibody | Rabbit anti-SNRPA1, 2-5 μg/ml (datasheet A10655-1) |
| Primary incubation | Overnight at 4 °C (datasheet A10655-1) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A10655-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SNRPA1-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Ubiquitous nuclear expression. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet A10655-1); the published lung protocol used citrate pH 6.0 (PMC10435942: methods).
Section 2
What Is the Expected SNRPA1 Staining Pattern?
SNRPA1 is a nuclear spliceosome protein with no transmembrane segment (UniProt P09661). In paraffin-section IHC, expect nuclear staining across many cell types, including glandular, respiratory epithelial and neuronal cells (HPA tissue IHC: ubiquitous nuclear expression). HPA rates the tissue pattern Supported because paired antibodies show similar staining and have external characterization data (HPA tissue IHC: reliability Supported).
| Distinct nuclear staining in glandular, respiratory epithelial or neuronal cells. | This fits the expected compartment and the High staining reported for those cell types in selected tissues (UniProt P09661: nucleus; HPA tissue IHC: High). Compare nuclei within the tissue rather than requiring every cell to have identical intensity (general IHC interpretation). |
| Predominantly cytoplasmic or membranous staining, with little nuclear signal. | Treat a compartment shift as suspect: UniProt places SNRPA1 in the nucleus, and HPA describes ubiquitous nuclear tissue staining (UniProt P09661; HPA tissue IHC). Review the counterstain and detection controls before calling it target signal (general IHC practice). |
| Strong staining in a cell population expected to show little signal. | Consider cross-reactivity or endogenous detection activity, especially if the stain lies outside nuclei (general IHC practice; UniProt P09661: nucleus). HPA reports Low staining in cardiomyocytes and skeletal myocytes, but lists no negative tissue; staining there alone does not prove an artefact (HPA tissue IHC). |
| Diffuse colour over nuclei, cytoplasm and surrounding tissue. | Broad background obscures the nuclear pattern and is insufficient to score as specific SNRPA1 staining (HPA tissue IHC: ubiquitous nuclear expression; general IHC interpretation). Check the reagent-omission control, blocking, washes and chromogen development as general detection variables (general IHC practice). |
| No nuclear signal in a selected known-positive section. | First verify tissue identity and an intact counterstain, then check the IHC-validated antibody and detection controls (general IHC practice). HPA reports High staining in adrenal gland glandular cells and bronchus respiratory epithelial cells; an absent signal there warrants troubleshooting, not an immediate biological-negative call (HPA tissue IHC). |
💡Expected SNRPA1 appearanceA convincing positive is predominantly nuclear staining in expected glandular, respiratory epithelial or neuronal cells, with High signal possible in the listed HPA tissues; dominant cytoplasmic colour is suspect (HPA tissue IHC: High and ubiquitous nuclear expression; UniProt P09661: nucleus).
| Where should the signal be scored? | Score nuclei in paraffin-section IHC: SNRPA1 is nuclear and participates in U2 spliceosome function (UniProt P09661). Nuclear speckles and bodies are additional ICC-IF locations; their visibility is not a requirement for chromogenic tissue IHC (HPA subcellular ICC-IF; general IHC interpretation). |
| Which tissue contrasts are supported? | Selected glandular, respiratory epithelial and neuronal populations are High, while cardiomyocytes and skeletal myocytes are Low (HPA tissue IHC). The record supplies no negative tissue, so Low muscle staining is a relative contrast rather than an absence standard (HPA tissue IHC). |
| How strong is the antibody evidence? | HPA rates the tissue profile Supported and lists HPA045622 and HPA048499 as Supported for IHC (HPA tissue IHC; HPA antibodies). Agreement between antibodies supports the pattern, but a new experiment still needs its own controls (general IHC practice). |
| Does processing predict a staining difference? | UniProt records no signal peptide or transmembrane segment, one annotated chain spanning residues 2–255, and no annotated isoforms (UniProt P09661). These annotations do not identify the catalog antibody's epitope or establish a fixation effect; interpret any altered staining with experimental controls (general IHC practice). |
| What should IF/ICC show? | HPA reports a supported main location in the nucleoplasm, with additional supported nuclear speckles and nuclear bodies in ICC-IF (HPA subcellular ICC-IF). This provides a localisation comparison for the separate IF/ICC guide; it does not specify an IHC protocol or require those structures to resolve in tissue sections (general IHC interpretation). |
| Situation | Likely cause | Next action |
|---|---|---|
| No stain in a High HPA cell population. | The assay may have failed, or the sampled section may lack the expected cells (general IHC practice). | Confirm tissue morphology and cell identity; run a known-positive section, reagent controls and the IHC-validated antibody's stated IHC-P conditions (HPA tissue IHC: High; general IHC practice). |
| Colour appears mainly outside nuclei. | The compartment conflicts with the documented nuclear pattern; nonspecific binding or detection background is possible (UniProt P09661; HPA tissue IHC; general IHC practice). | Compare with the nuclear counterstain and reagent-omission control; score SNRPA1 only where signal tracks nuclei (general IHC practice). |
| The whole section shows diffuse brown colour. | Excess background or endogenous detection activity can obscure cellular localisation (general chromogenic IHC practice). | Inspect omission controls, blocking and wash steps, and chromogen development; reassess whether nuclear contrast remains (general IHC practice). |
| Strong stain appears in cardiomyocytes or myocytes. | HPA describes these cells as Low, although neither is established as negative (HPA tissue IHC). | Compare nuclear localisation and intensity with a High reference population; investigate cross-reactivity or endogenous detection activity if the pattern is discordant (HPA tissue IHC; general IHC practice). |
| Nuclear staining varies across the section. | Cell composition or assay variation may affect the comparison; HPA gives a tissue profile rather than a uniform-intensity rule (HPA tissue IHC; general IHC interpretation). | Compare like cell types in well-preserved areas and inspect controls before assigning a biological difference (general IHC practice). |
| Speckles or nuclear bodies are not resolved. | Those additional locations come from ICC-IF images, whereas the tissue IHC profile is reported as nuclear (HPA subcellular ICC-IF; HPA tissue IHC). | Judge the chromogenic section by convincing nuclear staining in expected cells; use the separate IF/ICC guide when subnuclear localisation is the experimental question (HPA tissue IHC; general IHC interpretation). |
Experiment evidence
IHC & IF images showing SNRPA1 staining
A10655-1 · IHCIHC analysis of SNRPA1 using anti-SNRPA1 antibody (A10655-1). SNRPA1 was detected in a paraffin-embedded section of human glioblastoma tissu
A10655-1 · IHCIHC analysis of SNRPA1 using anti-SNRPA1 antibody (A10655-1). SNRPA1 was detected in a paraffin-embedded section of human larynx squamous ce
A10655-1 · IFIF analysis of SNRPA1 and Tubulin beta using anti-SNRPA1 antibody (A10655-1) and anti-Tubulin beta antibody (M05613-4). SNRPA1 and Tubulin b
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000131876-SNRPA1/tissue/cerebral+cortex#imid_12552623
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000131876-SNRPA1/tissue/colon#imid_12544207
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000131876-SNRPA1/tissue/liver#imid_12544192
HPA · PancreasHuman Protein Atlas IHC, Pancreas. Source: https://www.proteinatlas.org/ENSG00000131876-SNRPA1/tissue/pancreas#imid_12544151
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA045622; green = SNRPA1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA045622; green = SNRPA1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SNRPA1 IHC & IF
🧪Run bronchus first; respiratory epithelial cells should show nuclear staining (HPA: bronchus respiratory epithelial cells, High; UniProt P09661: nucleus). HPA detects SNRPA1 in all 45 scored tissues, so there is no supported negative tissue; use no-primary and isotype controls, and treat apparently unstained cells within the bronchus section as background references, not validated target-negative cells (HPA: no negative rows; detected in all 45 scored tissues).
Positive control tissue: Adrenal gland (Glandular cells, HPA High)
Negative control tissue: None in HPA: SNRPA1 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 SNRPA1 in A-431, U-251MG, U2OS, HEK293, RT-4, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide and an isotype control matched to the rabbit primary antibody’s class and clonality, plus SNRPA1 knockout material processed in parallel as a biological negative (selected-SKU caption: rabbit anti-SNRPA1). Quench endogenous peroxidase and inspect pigmented airway cells that could complicate brown DAB interpretation (selected-SKU caption: HRP/DAB; standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected-SKU paraffin-section caption does not state the fixative (selected-SKU caption: fixative unreported). That caption demonstrates EDTA retrieval at pH 8.0 for paraffin IHC, but does not establish that retrieval is universally required (selected-SKU caption: EDTA pH 8.0). Cultured-cell ICC-IF has a supported nucleoplasmic localisation benchmark, with additional speckle and nuclear-body signal, but the supplied evidence does not show that IF or frozen sections are easier than paraffin IHC; bronchial pigment can complicate DAB scoring (HPA: subcellular localisation; HPA: bronchus respiratory epithelial cells, High; standard IHC practice).
HPA tissue IHC evidence for SNRPA1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — Paired antibodies with high similarity and external characterization data supports antibody staining.). 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Breast | Glandular cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Caudate | Neuronal cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: SNRPA1 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced SNRPA1 IHC Tips
Use nuclear staining, matched controls and the documented paraffin-section conditions to troubleshoot SNRPA1 chromogenic IHC.
Which retrieval conditions should I try first for weak SNRPA1 staining?
Start with heat-mediated retrieval in EDTA at pH 8.0 (datasheet A10655-1). The documented paraffin-section workflow then used 10% goat serum blocking and 2 μg/ml primary antibody overnight at 4°C (caption A10655-1). If nuclear staining remains weak, check that the section stayed covered by retrieval buffer throughout heating, then compare a modest increase in heating time on adjacent sections while holding antibody and detection conditions constant (general IHC practice). Judge any gain against background and tissue morphology, using nuclei as the expected compartment for SNRPA1 (UniProt P09661: nucleus; HPA: ubiquitous nuclear expression).
Could fixation be responsible for variable nuclear staining?
Target-specific fixation sensitivity for SNRPA1 is unknown: the selected paraffin-section caption does not state a fixative (caption A10655-1). Record the actual fixative, fixation interval and processing history for each specimen before comparing staining, because these variables can affect antigen accessibility in IHC (general IHC practice). Compare adjacent sections with the same EDTA pH 8.0 retrieval and 2 μg/ml primary concentration so that fixation is the main changed variable (datasheet A10655-1; caption A10655-1). If signal varies across a section, inspect morphology and section adhesion before assigning the difference to SNRPA1 expression (general IHC practice).
Where should convincing SNRPA1 staining appear in a tissue section?
Score nuclear signal first: SNRPA1 is assigned to the nucleus, and tissue IHC shows ubiquitous nuclear expression (UniProt P09661: nucleus; HPA: tissue profile). Its principal reported subcellular location is the nucleoplasm, with additional nuclear speckles and nuclear bodies in ICC/IF data (HPA: subcellular localisation). Chromogenic DAB may not resolve those smaller nuclear structures in a paraffin section, so assess nuclear staining against a clear nuclear counterstain and intact morphology (general IHC practice). Predominantly cytoplasmic or extracellular colour should prompt review of background, detection and section quality before it is scored as SNRPA1 (UniProt P09661: nucleus; general IHC practice).
Could epitope choice explain staining differences between antibodies?
The supplied record lists 0 alternative isoforms, so an isoform-specific explanation is unsupported here (UniProt P09661: isoforms). SNRPA1 has no transmembrane segment or signal peptide, and its annotated chain spans residues 2–255 (UniProt P09661: topology and processing). It has an LRRCT domain at residues 123–161 and several annotated modified residues, including phosphoserines, but the catalog antibody's epitope is not supplied (UniProt P09661: domains and modified residues; supplied antibody data). If two antibodies disagree, compare their disclosed immunogens when available and test adjacent sections under each antibody's documented retrieval conditions before attributing the difference to an epitope or modification (general IHC practice).
How can I investigate SNRPA1 localisation by IF alongside tissue IHC?
Treat IF as a separately optimised assay; the selected antibody evidence describes chromogenic staining of a paraffin section, without IF fixation or permeabilisation conditions (caption A10655-1). For multiplex IF, pair SNRPA1 with a validated marker for the expected cell type in the specimen and choose spectrally separated fluorophores, favouring a far-red channel if tissue autofluorescence obscures shorter wavelengths (general IF practice). Because SNRPA1 is nuclear and has no transmembrane segment, optimise permeabilisation for antibody access to nuclear epitopes after the chosen fixation (UniProt P09661: nucleus and topology; general IF practice). Include single-stain and no-primary controls to check bleed-through, autofluorescence and background before comparing IF localisation with nuclear DAB staining (general IF practice; HPA: nucleoplasm supported).
How should I troubleshoot diffuse brown staining or noisy nuclei?
First compare the section with a no-primary control and inspect whether colour follows tissue folds, damaged edges or the expected nuclei (general IHC practice; UniProt P09661: nucleus). For peroxidase detection, confirm an effective endogenous peroxidase block and rinse thoroughly before DAB development (general IHC practice). The documented method used 10% goat serum blocking, 2 μg/ml rabbit primary overnight at 4°C, and a peroxidase-conjugated secondary for 30 minutes at 37°C (caption A10655-1). If background persists, compare shorter chromogen development or lower primary concentration on adjacent sections while checking that specific nuclear contrast remains (general IHC practice).
What is a defensible way to quantify SNRPA1 IHC? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and regions before scoring, then count only interpretable nuclear staining as SNRPA1 signal (UniProt P09661: nucleus; general IHC practice). Report the percentage of positive nuclei and intensity by category, or calculate a nuclear H-score from intensity-weighted percentages on a 0–300 scale (general IHC practice). Normalise cell counts to the number of evaluable cells, or report positive-cell density per mm² of viable tissue when region size differs (general IHC practice). Keep retrieval, staining batch, imaging and threshold settings consistent, and record excluded necrotic or damaged regions so comparisons reflect the sampled cells (general IHC practice).
How do I distinguish true SNRPA1 staining from artefact?
A credible result is staining in morphologically intact nuclei with a consistent pattern across comparable cells, because SNRPA1 is nuclear and HPA describes ubiquitous nuclear tissue expression (UniProt P09661: nucleus; HPA: tissue profile). Use the nuclear counterstain to reject apparent signal centred outside nuclei, and inspect abrupt edge staining, folds and necrotic areas separately (general IHC practice). Colour in vessels or other structures on a no-primary control can indicate endogenous enzyme activity or detection background, rather than antigen-specific signal (general IHC practice). HPA reports low staining in cardiomyocytes and skeletal myocytes, so interpret weak signal in those cells cautiously while preserving the actual tissue and morphology context (HPA: low in heart and skeletal muscle).
Boster reagents
Best SNRPA1 / U2 small nuclear ribonucleoprotein A' IHC Antibodies
A10655-1 has IHC images from human paraffin sections and IF images from human sections, mouse brain, and Caco-2 cells; M10655 lists IHC for human, mouse, and rat (catalog image captions; applications/reactivity).
Real IHC data
Anti-SNRPA1 Antibody ®
Cat # A10655-1
A10655-1 has illustrated IHC in human glioblastoma, larynx squamous cell carcinoma, liver cancer, and lung adenocarcinoma paraffin sections, plus IF in Caco-2 cells and human and mouse sections (A10655-1 image captions). M10655 lists IHC and human, mouse, and rat reactivity, but provides no IHC image caption in this payload (M10655 catalog applications/reactivity; image captions).
Which to pick: Choose A10655-1 for tissue IHC: its human paraffin-section captions document EDTA pH 8.0 retrieval and 2 μg/ml primary antibody; the fixative is unreported (A10655-1 IHC image captions). Choose A10655-1 for IF/ICC because those applications and corresponding images are listed; M10655 lists IHC only and is a rabbit monoclonal alternative for tissue IHC (catalog applications; M10655 clone field). For cross-species work, both list human, mouse, and rat reactivity, while A10655-1 additionally has illustrated mouse IF; the supplied IHC images are human only (catalog reactivity; A10655-1 image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P09661 (RU2A_HUMAN, U2 small nuclear ribonucleoprotein A').
- Human Protein Atlas. SNRPA1 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. SNRPA1 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the nuclear speckles and nuclear bodies..
- Human Protein Atlas. SNRPA1 antibody validation summary (2 antibodies).
- Elevated SNRPA1, as a Promising Predictor Reflecting Severe Clinical Outcome via Effecting Tumor Immunity for ccRCC, Is Related to Cell Invasion, Metastasis, and Sunitinib Sensitivity. Frontiers in immunology 2022 — PMC8904888.
- High SNRPA1 expression leads to poor prognosis in patients with lung adenocarcinoma. The clinical respiratory journal 2023 — PMC10435942.
- PubMed PMID:2928112 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SNRPA1 (U2 small nuclear ribonucleoprotein A'). Expected localisation Ubiquitous nuclear staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A10655-1). Validated IHC antibody: A10655-1 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (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 glioblastoma tissue; fixative not specified (datasheet A10655-1); 2. Fixation: Image fixative and duration unreported (datasheet A10655-1); 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 A10655-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A10655-1); 8. Primary antibody: Rabbit anti-SNRPA1, 2-5 μg/ml (datasheet A10655-1); 9. Primary incubation: Overnight at 4 °C (datasheet A10655-1). Watch for: Fixation: Keep paraffin-section fixation consistent between samples. (standard IHC practice; not target-specific); Caveat: Low signal in cardiomyocytes and skeletal myocytes (HPA tissue IHC); Isoform / epitope: 0 isoforms annotated; chain spans residues 2–255 (UniProt); Regulation: Tissue-specific regulation unannotated (UniProt). Evidence: UniProt P09661, HPA tissue IHC · Supported, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A10655-1, PMC10435942. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SNRPA1/immunohistochemistry-ihc-guide.