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LARP1 / La-related protein 1 · IHC design guide
Design Immunohistochemistry for LARP1
Plan LARP1 staining in paraffin sections using the reported cytoplasmic tissue pattern (HPA tissue IHC). This guide pairs tissue controls with the catalog antibody’s chromogenic IHC workflow (HPA tissue IHC; datasheet A04488-2).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
LARP1 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 cytoplasmic staining (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic signal in glandular and neuronal cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A04488-2) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Adipose tissue+2 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); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A04488-2) | |
| Caveat | Staining and RNA expression have medium consistency (HPA tissue IHC) | |
| Regulation | Nutrients regulate LARP1 activity (UniProt) | |
| Isoform / epitope | Two isoforms; antibody epitope coverage is unknown (UniProt; datasheet A04488-2) |
Section 1
Recommended LARP1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A04488-2) is paired with published LARP1 IHC protocols for colorectal cancer (PMC5126195) and clear cell renal cell carcinoma (PMC7933513).
| Sample | Paraffin-embedded human rectal cancer tissue; fixative not specified (datasheet A04488-2) |
| Fixation | Image fixative and duration unreported (datasheet A04488-2); 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 A04488-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A04488-2) |
| Primary antibody | Rabbit anti-LARP1, 2-5 μg/ml (datasheet A04488-2) |
| Primary incubation | Overnight at 4 °C (datasheet A04488-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A04488-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | LARP1-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 (datasheet A04488-2); sodium citrate retrieval is a published alternative for these tissues (PMC5126195; PMC7933513).
Section 2
What Is the Expected LARP1 Staining Pattern?
LARP1 is a cytoplasmic protein with no transmembrane segment; it can occur in cytoplasmic granules (UniProt Q6PKG0). In paraffin-section IHC, expect predominantly cytoplasmic staining in cells such as colonic glandular cells and cerebellar Purkinje cells (HPA: High in both). HPA describes general cytoplasmic expression, but rates its tissue IHC evidence Approved with medium staining–RNA consistency and pending external verification (HPA tissue IHC).
| Cytoplasmic chromogen in colonic or duodenal glandular cells, with little signal in adjacent unstained structures. | This fits the reported IHC compartment and two High cell populations (HPA: general cytoplasmic expression; High in colonic and duodenal glandular cells). Assess the named cells, rather than assigning one intensity to the entire tissue. |
| Predominantly nuclear staining in a paraffin section, without a convincing cytoplasmic component. | Recheck interpretation and staining controls: tissue IHC is described as generally cytoplasmic (HPA tissue IHC). Nuclear signal alone does not establish the expected IHC pattern; HPA separately reports nucleoplasmic localization in ICC-IF (HPA subcellular). |
| Strong chromogen in adipocytes, skeletal myocytes, or cervical glandular cells. | These cells are reported Not detected in HPA tissue IHC (HPA: adipocytes, skeletal myocytes, cervical glandular cells). Consider antibody cross-reactivity or endogenous detection activity (general IHC practice); the HPA result alone cannot identify which caused the signal. |
| Diffuse chromogen across cells and surrounding tissue, obscuring cell boundaries. | An even haze is difficult to reconcile with a cell-resolved cytoplasmic pattern (HPA: general cytoplasmic expression). Inspect the negative and detection controls for nonspecific binding, incomplete blocking, or detection background (general IHC practice). |
| No staining in colonic glandular cells or cerebellar Purkinje cells. | Both are reported High, so a blank result warrants a technical review (HPA: High in colonic glandular and Purkinje cells). Check section integrity, the antibody and detection controls, and retrieval conditions (general IHC practice); HPA does not establish LARP1-specific retrieval sensitivity. |
💡Expected LARP1 appearanceCall a positive result when the named High cells show discernible, predominantly cytoplasmic chromogen (HPA: High in colonic glandular and Purkinje cells; general cytoplasmic expression); isolated nuclear staining or signal confined to reported Not detected cells warrants review (HPA tissue IHC).
| Which compartment should guide IHC scoring? | Use the cytoplasm as the primary tissue-IHC reference (HPA: general cytoplasmic expression; UniProt Q6PKG0: cytoplasm). UniProt also describes granules resembling stress granules, but neither source requires puncta in every paraffin section (UniProt Q6PKG0). |
| How strong is the tissue-pattern evidence? | HPA calls tissue IHC Approved while reporting medium staining–RNA consistency and pending external verification (HPA tissue IHC). Two listed antibodies have Approved IHC status; this is not an Enhanced validation claim (HPA: HPA051397, HPA054819). |
| Do isoforms or modifications define a different stain? | UniProt lists 2 isoforms and multiple modified residues (UniProt Q6PKG0). Without an antibody epitope or isoform-specific validation in the supplied evidence, these facts cannot assign a stain to one isoform or explain loss of signal. |
| Does antigen retrieval have a LARP1-specific predicted effect? | Retrieval is a standard variable to optimize in paraffin-section IHC (general IHC practice). Neither HPA nor UniProt supplies a LARP1-specific retrieval or fixation effect, so changes in signal cannot be predicted from the tissue levels or protein topology. |
| Should IF/ICC show the same compartment as tissue IHC? | IF/ICC has its own guide. HPA reports nucleoplasm and endoplasmic reticulum as Approved ICC-IF locations and cytosol as Supported (HPA subcellular); those observations should not be substituted for the general cytoplasmic tissue-IHC profile (HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Known High cells are blank while the counterstain is visible. | Possible failure of antibody binding or chromogenic detection (general IHC practice); the HPA High designation does not establish a fixation cause (HPA tissue IHC). | Check a documented positive section and detection control, then review antibody use and retrieval conditions (general IHC practice). Judge the result in the named glandular or Purkinje cells (HPA: High). |
| Only nuclei appear positive in tissue IHC. | Compartment assignment or nonspecific staining may be involved (general IHC practice). Tissue IHC is generally cytoplasmic, although ICC-IF also reports nucleoplasm (HPA tissue IHC; HPA subcellular). | Compare nuclear and cytoplasmic boundaries under the counterstain and inspect controls (general IHC practice). Record the discrepancy instead of treating the ICC-IF location as tissue-IHC confirmation. |
| Adipocytes or skeletal myocytes stain strongly. | Unexpected signal in cells reported Not detected may reflect cross-reactivity or endogenous chromogenic activity (HPA tissue IHC; general IHC practice). | Review the negative and detection-only controls and cell identity; adjust blocking or detection conditions if controls show background (general IHC practice). |
| A uniform brown haze prevents cytoplasmic scoring. | Nonspecific background or excess chromogen can obscure the cell-resolved pattern (general IHC practice; HPA: general cytoplasmic expression). | Inspect the negative control and detection timing, then optimize blocking, antibody concentration, and washes (general IHC practice). Score only after cell boundaries can be resolved. |
| Staining differs between High tissues or within a section. | HPA assigns intensity to named cell populations, and its tissue IHC has medium staining–RNA consistency (HPA tissue IHC). Tissue-wide averages may conceal which cells contribute signal. | Score the specified cell population and cytoplasmic compartment separately in each section (HPA tissue IHC; general IHC practice). Document deviations without assigning an unsupported LARP1-specific fixation effect. |
Experiment evidence
IHC & IF images showing LARP1 staining
A04488-2 · IHCIHC analysis of LARP1 using anti-LARP1 antibody (A04488-2). LARP1 was detected in a paraffin-embedded section of human rectal cancer tissue.
A04488-2 · IHCIHC analysis of LARP1 using anti-LARP1 antibody (A04488-2). LARP1 was detected in a paraffin-embedded section of mouse brain tissue. Heat me
A04488-2 · IFIF analysis of LARP1 using anti-LARP1 antibody (A04488-2). LARP1 was detected in an immunocytochemical section of CACO-2 cells. Enzyme antig
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000155506-LARP1/tissue/cerebral+cortex#imid_16813547
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000155506-LARP1/tissue/colon#imid_16813473
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000155506-LARP1/tissue/liver#imid_16813474
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000155506-LARP1/tissue/kidney#imid_16813467
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB015222; green = LARP1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB015222; green = LARP1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for LARP1 IHC & IF
🧪Run colon first: glandular cells should stain (HPA: High in colon glandular cells). Use skeletal muscle myocytes as the negative tissue (HPA: Not detected in skeletal muscle myocytes); on the colon slide, cells without specific staining should show only counterstain or background, without assuming a particular neighboring cell type is negative (standard IHC practice).
Positive control tissue: Appendix (Glandular cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show LARP1 in A-431, U-251MG, U2OS, with annotated localisation: Nucleoplasm (approved), Endoplasmic reticulum (approved), Cytosol (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control, a rabbit IgG isotype control matched to the primary antibody’s clonality and concentration, and a LARP1 knockout sample or peptide-block control if available (A04488-2 caption: rabbit primary; standard IHC practice). Block endogenous peroxidase and check inflammatory cells in colon for nonspecific DAB signal (standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected paraffin-section caption does not state the fixative (A04488-2 caption: fixative unreported). Heat retrieval in EDTA at pH 8.0 was used, but retrieval dependence was not established (A04488-2 caption). Paraffin-section IHC is documented and ICC-IF images exist, while the supplied evidence does not establish that frozen sections or IF are easier; check colonic inflammatory cells for endogenous peroxidase background (A04488-2 caption; HPA: ICC-IF images in A-431, U-251MG and U2OS; standard IHC practice).
HPA tissue IHC evidence for LARP1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium consistency between antibody staining and RNA expression data. Pending external verification.). 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 → |
| Cerebral cortex | Neuronal cells | High | Protein (IHC) | HPA → |
| Colon | Glandular cells | High | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | High | Protein (IHC) | HPA → |
Section 3
Advanced LARP1 IHC Tips
Troubleshoot LARP1 staining in paraffin sections by checking retrieval, controls, cell compartment, and scoring before interpreting changes in signal.
Which antigen retrieval condition should I start with for LARP1 IHC?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A04488-2). The selected tissue image used this retrieval before antibody incubation at 2 μg/ml overnight at 4°C (caption A04488-2). If staining is weak, compare serial sections with modest changes in heating duration while keeping EDTA and section handling constant (standard IHC practice). Include a known positive glandular compartment, such as colon, and assess whether signal improves without spreading into stroma or section edges (HPA: high in colon glandular cells; standard IHC practice). Document each retrieval condition alongside its negative control, because excess heat can increase tissue damage and apparent background (standard IHC practice).
Could fixation explain weak LARP1 staining in my paraffin sections?
The selected paraffin-section caption does not state a fixative, so LARP1-specific fixation sensitivity is unknown (caption A04488-2). Record fixative, time to fixation, and fixation duration for each specimen, then compare matched sections when a protocol change is necessary (standard IHC practice). Avoid interpreting weak cytoplasmic staining as fixation loss until retrieval, antibody concentration, and detection controls have been checked (HPA: general cytoplasmic expression; standard IHC practice). The published workflow supplies EDTA pH 8.0 retrieval and 2 μg/ml antibody overnight at 4°C, but no fixation benchmark (caption A04488-2). Score morphology and staining together, excluding poorly preserved or necrotic regions from comparisons (standard IHC practice).
How should I assess an unexpected nuclear or membrane LARP1 pattern?
Expect cytoplasmic chromogenic signal in tissue sections, since the tissue profile describes general cytoplasmic expression (HPA: tissue IHC profile). LARP1 also localizes to cytoplasmic granules and has no transmembrane segment, so membrane-only staining is discordant (UniProt Q6PKG0: localization and topology). Cultured-cell imaging reports nucleoplasm, endoplasmic reticulum, and cytosol; this does not establish their balance in paraffin sections (HPA: subcellular). Compare glandular or neuronal compartments with neighboring cells using identical DAB development and a negative reagent control (HPA: high in colon glandular cells and cerebellar Purkinje cells; standard IHC practice). Investigate nuclear-only DAB if cytoplasmic positive controls fail (HPA: tissue IHC profile; standard IHC practice).
Can a staining difference identify a LARP1 isoform or modified epitope?
LARP1 has 2 annotated isoforms, but the selected antibody caption provides no epitope map or isoform-specific validation (UniProt Q6PKG0: isoforms; caption A04488-2). Its La-type RNA-binding domain spans residues 397–487, and several phosphorylation sites are annotated, including serines 75 and 90 (UniProt Q6PKG0: domains and modified residues). Neither domain location nor phosphorylation annotation identifies the antibody's binding site or predicts retrieval sensitivity (UniProt Q6PKG0; standard assay interpretation). When staining changes across specimens, first compare matched sections under one EDTA pH 8.0 retrieval and detection run (caption A04488-2; standard IHC practice). Claim isoform-selective or modification-sensitive staining only after independent epitope or perturbation evidence is obtained (standard antibody validation practice).
How should I investigate LARP1 localization with companion IF?
For companion IF, multiplex LARP1 with a marker identifying glandular cells, which show high staining in colon (HPA: colon glandular cells). Choose a far-red channel when tissue autofluorescence compromises shorter wavelengths, and check single-label and no-primary controls before interpreting overlap (standard IF practice). Permeabilise for intracellular cytosolic, endoplasmic-reticulum, or nucleoplasmic epitopes; LARP1 has no transmembrane segment, although this antibody's epitope is unreported (HPA: subcellular; UniProt Q6PKG0: topology; caption A04488-2). The paraffin image establishes chromogenic staining with EDTA pH 8.0 retrieval and 2 μg/ml antibody, but supplies no IF conditions (caption A04488-2). Interpret puncta against the cytoplasmic-granule annotation and exclude autofluorescent structures (UniProt Q6PKG0: cytoplasmic granules; standard IF practice).
What should I check when LARP1 DAB staining is diffuse?
Check section-wide DAB haze against a no-primary control and the expected cytoplasmic pattern (standard IHC practice; HPA: tissue IHC profile). The selected image used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, and a peroxidase-conjugated secondary (caption A04488-2). If background persists, titrate primary concentration or shorten DAB development while preserving a positive glandular compartment (HPA: high in colon glandular cells; standard IHC practice). Apply peroxidase blocking and inspect endogenous enzyme contribution as general chromogenic IHC controls; neither is established as LARP1-specific (standard IHC practice; caption A04488-2). Evaluate folds, edges, and necrosis separately from intact tissue before changing retrieval (standard IHC practice).
How should I quantify LARP1 staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION
Score cytoplasmic DAB within a prespecified cell compartment, because tissue IHC describes general cytoplasmic LARP1 expression (HPA: tissue IHC profile). An H-score sums percentages at intensity 1, 2, and 3 multiplied by their intensity, yielding 0–300 (standard IHC scoring practice). Alternatively, report percent positive cells or positive-cell density per mm², with identical thresholds and sampled areas (standard IHC practice). Normalize to viable cells of the same type or viable compartment area, excluding necrosis and non-target stroma (standard IHC practice). Include control-section performance and staining batch, because HPA reports medium RNA-staining consistency and awaits external verification (HPA: reliability description; standard IHC practice).
How can I distinguish credible LARP1 staining from artefact?
Credible DAB staining is mainly cytoplasmic in intact cells and reproducible across sections and controls (HPA: tissue IHC profile; standard IHC practice). High colon glandular-cell signal is plausible; strong adipocyte staining conflicts with their reported undetected profile (HPA: colon glandular cells high; adipocytes not detected). Membrane-only outlines conflict with LARP1's cytoplasmic annotation and absent transmembrane segment; investigate nuclear-only staining with orthogonal evidence (UniProt Q6PKG0: localization and topology; HPA: subcellular). Discount section-edge staining or necrotic debris, and check endogenous peroxidase with a no-primary control (standard IHC practice). Stronger DAB alone cannot establish mTORC1 activation or phosphorylation state (UniProt Q6PKG0: function; standard assay interpretation).
Boster reagents
Best LARP1 / La-related protein 1 IHC Antibodies
A04488-2 has IHC images from paraffin sections of human rectal cancer and mouse brain, plus an ICC/IF image from CACO-2 cells (A04488-2 image captions).
Real IHC data
Anti-LARP1 Antibody ®
Cat # A04488-2
A04488-2 was shown in IHC on paraffin sections of human rectal cancer and mouse brain (A04488-2 IHC captions). A04488-2 was also shown in ICC/IF on CACO-2 cells (A04488-2 IF caption).
Which to pick: For tissue IHC, choose A04488-2: its own images show paraffin sections with EDTA retrieval at pH 8.0; the fixative is unreported (A04488-2 IHC captions). For IF/ICC, choose A04488-2 based on its CACO-2 image and listed IF/ICC applications (A04488-2 IF caption; catalog applications). It is also the listed human/mouse option (catalog reactivity: Human, Mouse); clonality is unreported.
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q6PKG0 (LARP1_HUMAN, La-related protein 1).
- Human Protein Atlas. LARP1 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. LARP1 subcellular location (ICC-IF): Localized to the nucleoplasm, endoplasmic reticulum and cytosol..
- Human Protein Atlas. LARP1 antibody validation summary (3 antibodies).
- Overexpression of LARP1 predicts poor prognosis of colorectal cancer and is expected to be a potential therapeutic target. Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine 2016 — PMC5126195.
- LARP1 predict the prognosis for early-stage and AFP-normal hepatocellular carcinoma. Journal of translational medicine 2013 — PMC3814951.
- Downregulation of the lncRNA ASB16-AS1 Decreases LARP1 Expression and Promotes Clear Cell Renal Cell Carcinoma Progression via miR-185-5p/miR-214-3p. Frontiers in oncology 2020 — PMC7933513.
- The role of LARP1 in breast cancer progression: from prognosis to immune microenvironment remodeling. Frontiers in endocrinology 2026 — PMC13314501.
- PubMed PMID:15489334 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:9872452 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for LARP1 (La-related protein 1). Expected localisation General cytoplasmic staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A04488-2). Validated IHC antibody: A04488-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human rectal cancer tissue; fixative not specified (datasheet A04488-2); 2. Fixation: Image fixative and duration unreported (datasheet A04488-2); 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 A04488-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A04488-2); 8. Primary antibody: Rabbit anti-LARP1, 2-5 μg/ml (datasheet A04488-2); 9. Primary incubation: Overnight at 4 °C (datasheet A04488-2). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A04488-2); Caveat: Staining and RNA expression have medium consistency (HPA tissue IHC); Isoform / epitope: Two isoforms; antibody epitope coverage is unknown (UniProt; datasheet A04488-2); Regulation: Nutrients regulate LARP1 activity (UniProt). Evidence: UniProt Q6PKG0, HPA tissue IHC · Approved, HPA ICC-IF · nucleoplasm, endoplasmic reticulum and cytosol., Datasheet A04488-2, PMC5126195, PMC7933513. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/LARP1/immunohistochemistry-ihc-guide.