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LARP4B / La-related protein 4B · IHC design guide
Design Immunohistochemistry for LARP4B
Plan LARP4B paraffin IHC around the cytoplasmic and membranous tissue pattern (HPA tissue IHC). Select a high-staining glandular or squamous cell population as a positive reference, and interpret results cautiously because staining and RNA expression show low consistency (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
LARP4B 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 | Cytoplasmic and membranous tissue staining (HPA tissue IHC) | |
| Staining pattern | Glandular and squamous cells: cytoplasmic/membranous (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A08433-1) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across compared paraffin sections. (selected-SKU IHC image A08433-1) | |
| Caveat | Staining and RNA expression show low consistency (HPA tissue IHC) | |
| Regulation | No tissue-specific regulation annotated (UniProt) | |
| Isoform / epitope | No isoforms annotated; one chain spans residues 1–738 (UniProt) |
Section 1
Recommended LARP4B IHC & IF Protocols
The catalog antibody protocol provides the starting IHC-P conditions (datasheet: A08433-1). One published study adds examples from mouse osteosarcoma and human tumor tissue arrays (PMC10963253).
| Sample | Paraffin-embedded human appendiceal adenocarcinoma tissue; fixative not specified (datasheet A08433-1) |
| Fixation | Image fixative and duration unreported (datasheet A08433-1); 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 A08433-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A08433-1) |
| Primary antibody | Rabbit anti-LARP4B, 2-5 μg/ml (datasheet A08433-1) |
| Primary incubation | Overnight at 4 °C (datasheet A08433-1) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A08433-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | LARP4B-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic and membranous expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 (datasheet: A08433-1); the published excerpt does not specify its retrieval conditions (PMC10963253).
Section 2
What Is the Expected LARP4B Staining Pattern?
LARP4B is mainly cytosolic (UniProt Q92615; HPA: cytosol). In paraffin-section IHC, expect cytoplasmic staining in glandular cells of the colon, appendix and breast, and squamous epithelial cells of the cervix and esophagus (HPA: High in each). HPA also reports membranous staining in most tissues (HPA: tissue profile). Interpret cautiously: tissue IHC is Approved, with low staining–RNA consistency and external verification pending (HPA: reliability). LARP4B has no transmembrane segment (UniProt Q92615 topology).
| Clear cytoplasmic chromogen in colon glandular cells or cervix squamous epithelial cells. | This fits the reported High staining in those cells (HPA: tissue IHC). Assess signal within the expected cell type and compartment; a positive slide alone does not resolve HPA’s low staining–RNA consistency (HPA: reliability). |
| Predominantly nuclear signal, with little cytoplasmic staining. | A nuclear-dominant pattern conflicts with the cytosolic localisation (UniProt Q92615; HPA: cytosol). Review morphology, counterstain and detection background before calling it LARP4B (standard IHC practice). |
| Strong signal confined to cells reported as unstained, such as cardiomyocytes or adipocytes. | HPA reports LARP4B as Not detected in those cells (HPA: tissue IHC). Check for cross-reactivity or endogenous detection activity (standard IHC practice); this observation alone cannot distinguish them. |
| Diffuse chromogen covers tissue, stroma and spaces between cells. | That distribution does not establish the cell-associated cytoplasmic pattern (HPA: tissue profile; standard IHC interpretation). Inspect a no-primary control and review blocking, washing and detection conditions (standard IHC practice). |
| No signal in glandular cells of a colon or appendix section. | Both are reported High in those cells (HPA: tissue IHC). First check tissue preservation, control performance and the IHC workflow (standard IHC practice). HPA’s Approved rating still carries a low-consistency caveat (HPA: reliability). |
💡Expected LARP4B appearanceCall a result consistent when cytoplasmic staining is clear in reported High epithelial cells (HPA: tissue IHC; UniProt Q92615); isolated nuclear staining or uniform chromogen outside cells warrants review (HPA: cytosol; standard IHC interpretation).
| Tissue and cell selection | Colon and appendix glandular cells are reported High; cardiomyocytes and adipocytes are Not detected (HPA: tissue IHC). Compare the named cells, since a whole-section score can hide which population stained (standard IHC practice). |
| Compartment and topology | UniProt places LARP4B in the cytosol and reports no transmembrane segment (UniProt Q92615). HPA reports cytoplasmic and membranous tissue staining (HPA: tissue profile); assess membrane-accented signal alongside the cytoplasm rather than assuming membrane signal proves a membrane-bound protein. |
| Antibody evidence | HPA036566 has Approved IHC status; HPA042738 has no listed IHC status (HPA: antibodies). The tissue profile has low staining–RNA consistency and awaits external verification (HPA: reliability), so corroborate an unexpected pattern before interpreting it biologically (standard IHC practice). |
| IF/ICC Q: What localisation should I expect? | A: Mainly cytosolic fluorescence (HPA: ICC-IF, enhanced cytosol; UniProt Q92615). HPA lists ICC-IF images from A-431, U-251MG and U2OS, and Supported ICC status for both listed antibodies (HPA: subcellular; HPA: antibodies). |
| Target-specific fixation sensitivity | No LARP4B fixation-effect evidence is supplied (UniProt Q92615; HPA: supplied records). Treat retrieval adjustments as general IHC optimisation; do not infer that fixation explains a tissue-specific positive or negative result. |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected-positive glandular cells remain blank. | A failed stain or an unsuitable section is possible (standard IHC practice); colon glandular cells are reported High (HPA: tissue IHC). | Check the run controls, tissue morphology, primary-antibody step and chromogenic detection; optimise retrieval using a controlled comparison if needed (standard IHC practice). |
| All structures show faint, diffuse colour. | Non-specific background or endogenous detection activity can obscure cell-associated signal (standard IHC practice). | Compare a no-primary control, then review blocking, washes, detection exposure and counterstain (standard IHC practice). Score only interpretable cellular staining. |
| Nuclei stain more strongly than cytoplasm. | Nuclear dominance disagrees with the cytosolic localisation (UniProt Q92615; HPA: cytosol); background or cross-reactivity remains possible (standard IHC interpretation). | Check the counterstain and no-primary control, then repeat with adjusted detection conditions or corroborate with an independently validated reagent (standard IHC practice). |
| Only sharp cell outlines stain. | HPA reports membranous as well as cytoplasmic tissue staining, while UniProt reports no transmembrane segment (HPA: tissue profile; UniProt Q92615 topology). | Inspect whether cytoplasm also stains in the expected cells, and compare controls before assigning a membrane-only pattern to LARP4B (standard IHC practice). |
| Cardiomyocytes or adipocytes stain strongly. | Those cells are reported Not detected (HPA: tissue IHC). Cross-reactivity or endogenous detection activity is possible (standard IHC practice). | Locate the signal within the named cells, compare a no-primary control and seek independent corroboration before reporting LARP4B expression (standard IHC practice). |
| A low-signal tissue appears negative. | Parathyroid glandular cells are reported Low (HPA: tissue IHC); a negative call there is less informative than a failed reported-High control. | Assess a reported-High tissue in the same run and document the detection threshold before interpreting the low-signal section (HPA: tissue IHC; standard IHC practice). |
Experiment evidence
IHC & IF images showing LARP4B staining
A08433-1 · IHCIHC analysis of LARP4B using anti-LARP4B antibody (A08433-1). LARP4B was detected in a paraffin-embedded section of human appendiceal adenoc
A08433-1 · IHCIHC analysis of LARP4B using anti-LARP4B antibody (A08433-1). LARP4B was detected in a paraffin-embedded section of human liver cancer tissu
A08433-1 · IFIF analysis of LARP4B using anti-LARP4B antibody (A08433-1). LARP4B was detected in an immunocytochemical section of A431 cells. Enzyme anti
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000107929-LARP4B/tissue/cerebral+cortex#imid_9071116
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000107929-LARP4B/tissue/colon#imid_9072970
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000107929-LARP4B/tissue/liver#imid_9072971
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000107929-LARP4B/tissue/kidney#imid_9072980
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA036566; green = LARP4B, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA036566; green = LARP4B, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for LARP4B IHC & IF
🧪Run appendix first and expect glandular cells to stain (HPA: High in appendix glandular cells). Use adipose tissue as the negative tissue and expect adipocytes to lack detectable staining (HPA: Not detected in adipocytes); on the appendix slide, use adjacent cells without signal as an internal background reference without assuming they are target-negative.
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 LARP4B in A-431, U-251MG, U2OS, with annotated localisation: Cytosol (enhanced) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and a concentration-matched rabbit IgG isotype control (caption: rabbit primary antibody), plus LARP4B knockout tissue or peptide competition when a suitable reagent is available. Check for endogenous peroxidase and biotin background in appendix sections because the reported detection uses a biotin-based complex and DAB (caption: SABC/DAB).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A08433-1 tissue-IHC caption does not state the fixative. That caption reports heat retrieval in EDTA at pH 8.0 before paraffin-section staining; retrieval dependence and whether frozen sections or IF are easier remain unreported (caption: EDTA retrieval; HPA: cytosolic ICC-IF signal). Interpret glandular staining with specimen type in mind: the caption shows appendiceal adenocarcinoma, while the HPA positive row names appendix glandular cells (caption: appendiceal adenocarcinoma; HPA: High in appendix glandular cells).
HPA tissue IHC evidence for LARP4B
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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 → |
| Breast | Glandular 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 |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | Not detected | Protein (IHC) | HPA → |
| Ovary | Ovarian stroma cells | Not detected | Protein (IHC) | HPA → |
| Skeletal muscle | Myocytes | Not detected | Protein (IHC) | HPA → |
| Smooth muscle | Smooth muscle cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced LARP4B IHC Tips
Troubleshooting LARP4B staining in paraffin sections starts with the catalog antibody’s documented retrieval conditions and a cytosolic staining expectation (datasheet A08433-1; UniProt Q92615).
What should I change when LARP4B staining is weak after antigen retrieval?
Start with heat mediated retrieval in EDTA at pH 8.0 (datasheet A08433-1). The documented paraffin section workflow used 2 μg/ml primary antibody overnight at 4°C, so check those variables alongside retrieval before interpreting weak signal as absent protein (datasheet A08433-1). Compare sections processed with matched heating and cooling conditions, since uneven retrieval can create apparent differences across a run (standard IHC practice). If staining remains weak, trial another retrieval condition on adjacent sections as a fallback, recording tissue preservation and background as well as signal (standard IHC practice). Judge improvement in glandular cells with expected cytoplasmic staining, rather than by overall DAB intensity (HPA tissue IHC; UniProt Q92615).
Can I attribute faint LARP4B staining to the tissue fixative?
The selected image documents a paraffin embedded section, but its caption does not state the fixative (datasheet A08433-1). Target specific sensitivity to fixation is therefore unknown from the supplied evidence; neither the tissue staining pattern nor the protein’s topology or modifications establishes such an effect (datasheet A08433-1; HPA tissue IHC; UniProt Q92615). Record the actual fixative and fixation duration for each specimen, then compare matched sections with the same retrieval and detection conditions (standard IHC practice). Check morphology and staining in an expected positive compartment before changing processing conditions (HPA tissue IHC; standard IHC practice). Report any fixation association as an observation from that comparison, rather than a demonstrated property of LARP4B (standard IHC practice).
How should I assess membranous or nuclear LARP4B staining?
Prioritize cytoplasmic signal because LARP4B is assigned to the cytosol, and cell imaging reports mainly cytosolic localization (UniProt Q92615; HPA subcellular). The tissue profile also describes cytoplasmic and membranous expression in most tissues, so membrane adjacent DAB should be documented separately from diffuse cytoplasm (HPA tissue IHC). LARP4B has no transmembrane segment, which makes a sharply exclusive membrane pattern a reason to review specificity and section morphology (UniProt Q92615; standard IHC practice). Its reported accumulation in cytoplasmic mRNP granules follows arsenite treatment; that observation alone does not predict puncta in routine tissue sections (UniProt Q92615). Compare suspect patterns with a no primary control and an expected positive compartment before calling them LARP4B (standard IHC practice).
Could epitope location explain discordant LARP4B staining?
The supplied protein record lists 0 annotated isoforms, so it does not support an isoform specific explanation for discordant staining (UniProt Q92615). The record places a La type RNA binding region at residues 150–239 and an RRM at 240–307, but the selected caption does not identify the antibody’s epitope (UniProt Q92615; datasheet A08433-1). Several modified residues are annotated, including phosphoserine 244 and methylarginines 404 and 419; their effect on this antibody is unknown (UniProt Q92615). Review available immunogen documentation before proposing epitope masking or modification sensitivity (standard IHC practice). For discrepant sections, compare staining under identical retrieval and detection conditions, and seek independent antibody or orthogonal evidence before assigning an epitope mechanism (standard IHC practice).
How can IF help investigate an ambiguous chromogenic LARP4B pattern?
Use IF as a separate localization check for an ambiguous IHC pattern, while treating the paraffin section caption as evidence only for the documented chromogenic workflow (datasheet A08433-1; standard IHC practice). Multiplex LARP4B with an epithelial cell marker when assessing glandular staining, and inspect individual channels before assigning signal to a cell (HPA tissue IHC; standard IF practice). Choose a fluorophore channel after checking tissue autofluorescence and include single stain controls to assess channel bleed through (standard IF practice). Because LARP4B is cytosolic and lacks a transmembrane segment, permeabilisation must allow antibody access to the intracellular epitope; the antibody’s exact epitope is not supplied (UniProt Q92615; datasheet A08433-1). Compare cytosolic distribution across modalities without treating IF conditions as an IHC protocol (HPA subcellular; standard IF practice).
What should I troubleshoot when DAB appears throughout the section?
The documented workflow used 10% goat serum, a biotinylated secondary antibody, streptavidin biotin detection, and DAB (datasheet A08433-1). Diffuse colour may reflect nonspecific antibody binding or detection background, so inspect no primary and detection only controls alongside the stained section (standard IHC practice). Include a peroxidase block and check its effectiveness because endogenous enzyme activity can also produce chromogenic signal; this is a general IHC control, not evidence about LARP4B (standard IHC practice). If controls are clean, titrate primary antibody around the documented 2 μg/ml condition while keeping retrieval and DAB development consistent (datasheet A08433-1; standard IHC practice). Assess whether remaining signal follows the expected cytoplasmic distribution rather than uniform tissue colour (UniProt Q92615; standard IHC practice).
How should I score heterogeneous LARP4B staining across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and cytoplasmic compartment before scoring, because LARP4B is mainly cytosolic and tissue staining varies by cell type (UniProt Q92615; HPA tissue IHC). For glandular regions, record the percentage of positive cells and staining intensity, or calculate an H-score from intensity weighted cell percentages using the same thresholds across sections (standard IHC practice). For spatial counts, report positive cells per mm² of evaluable tissue and exclude necrotic or folded areas (standard IHC practice). Normalize comparisons to the number of evaluable cells or tissue area, as appropriate, and keep retrieval, exposure to DAB, and image settings consistent (standard IHC practice). Report membranous staining separately so it does not inflate a cytoplasmic score (HPA tissue IHC; standard IHC practice).
What evidence distinguishes true LARP4B signal from artefact?
A plausible result places signal mainly in cytoplasm, consistent with the protein record and cell imaging, while allowing the reported tissue profile’s membranous component to be assessed separately (UniProt Q92615; HPA subcellular; HPA tissue IHC). Appendix glandular cells are a reported high staining population, whereas adipocytes and cardiomyocytes are reported as not detected; use these as context rather than absolute controls (HPA tissue IHC). Review exclusive nuclear staining, section edge enhancement, necrotic areas, and colour persisting in no primary controls as possible artefacts (standard IHC practice). Check endogenous peroxidase background when interpreting DAB and compare cell identity and compartment in adjacent intact tissue (standard IHC practice). HPA labels its tissue staining approved but notes low consistency with RNA data and pending external verification, so avoid treating a single positive stain as conclusive specificity evidence (HPA tissue IHC).
Boster reagents
Best LARP4B / La-related protein 4B IHC Antibodies
A08433-1 has IHC images from human paraffin sections (catalog IHC captions) and an IF image from A431 cells (catalog IF caption); its listed reactivity is human (catalog: reactivity).
Real IHC data
Anti-LARP4B Antibody ®
Cat # A08433-1
A08433-1 is listed for IHC and IF/ICC in human samples (catalog: applications, reactivity), with IHC images from paraffin sections of human appendiceal adenocarcinoma and liver cancer (catalog IHC captions). Its IF image uses A431 cells (catalog IF caption).
Which to pick: For tissue IHC, choose A08433-1: its own images show human paraffin sections with EDTA retrieval at pH 8.0 (catalog IHC captions); the fixative is unreported (catalog IHC captions). For IF/ICC, the same SKU lists both applications and has an A431 cell IF image (catalog: applications; catalog IF caption). No cross-species option is established: A08433-1 lists human reactivity only, and its clonality is unreported (catalog: reactivity, clone field).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q92615 (LAR4B_HUMAN, La-related protein 4B).
- Human Protein Atlas. LARP4B tissue IHC expression (reliability: Approved).
- Human Protein Atlas. LARP4B subcellular location (ICC-IF): Mainly localized to the cytosol..
- Human Protein Atlas. LARP4B antibody validation summary (2 antibodies).
- The RNA binding proteins LARP4A and LARP4B promote sarcoma and carcinoma growth and metastasis. iScience 2024 — PMC10963253.
- PubMed PMID:9039502 — UniProt-cited evidence.
- PubMed PMID:12168954 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for LARP4B (La-related protein 4B). Expected localisation Cytoplasmic and membranous tissue staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A08433-1). Validated IHC antibody: A08433-1 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 appendiceal adenocarcinoma tissue; fixative not specified (datasheet A08433-1); 2. Fixation: Image fixative and duration unreported (datasheet A08433-1); 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 A08433-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A08433-1); 8. Primary antibody: Rabbit anti-LARP4B, 2-5 μg/ml (datasheet A08433-1); 9. Primary incubation: Overnight at 4 °C (datasheet A08433-1). Watch for: Fixation: Keep fixation consistent across compared paraffin sections. (selected-SKU IHC image A08433-1); Caveat: Staining and RNA expression show low consistency (HPA tissue IHC); Isoform / epitope: No isoforms annotated; one chain spans residues 1–738 (UniProt); Regulation: No tissue-specific regulation annotated (UniProt). Evidence: UniProt Q92615, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the cytosol., Datasheet A08433-1, PMC10963253. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/LARP4B/immunohistochemistry-ihc-guide.