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LRG1 / Leucine-rich alpha-2-glycoprotein · IHC design guide
Design Immunohistochemistry for LRG1
Plan paraffin-section LRG1 IHC around distinct plasma positivity (HPA tissue IHC) and its secreted location (UniProt). Use the high Paneth-cell staining in duodenum as a reference (HPA tissue IHC) alongside the catalog antibody’s documented chromogenic workflow (datasheet A04365-3).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
LRG1 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 | Secreted (UniProt); plasma positivity (HPA tissue IHC) | |
| Staining pattern | Distinct plasma positivity; Paneth cells high (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A04365-3) | |
| Positive control | Duodenum+3 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 sections (standard IHC practice; not target-specific) | |
| Caveat | Secretion can separate tissue staining from local RNA expression (HPA tissue IHC) | |
| Regulation | Liver-enriched RNA (HPA tissue RNA) | |
| Isoform / epitope | No isoforms annotated; mature chain starts at residue 36 (UniProt) |
Section 1
Recommended LRG1 IHC & IF Protocols
The catalog antibody protocol is paired with 4 published LRG1 IHC protocols from hepatobiliary, eye, mouse knee joint, and colon specimens (PMC3241550; PMC8396268; PMC5386532; PMC11436608).
| Sample | Paraffin-embedded human pancreas cancer tissue; fixative not specified (datasheet A04365-3) |
| Fixation | Image fixative and duration unreported (datasheet A04365-3); 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 A04365-3); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A04365-3) |
| Primary antibody | Rabbit anti-LRG1, 2-5 μg/ml recommended; image 1:100 (datasheet A04365-3) |
| Primary incubation | Overnight at 4 °C (datasheet A04365-3) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A04365-3) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | LRG1-positive staining in paneth cells of duodenum (HPA tissue IHC: High). HPA tissue profile: Distinct positivity in plasma. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval for the catalog antibody (datasheet A04365-3); the colon protocol reports microwave retrieval in citric acid (PMC11436608).
Section 2
What Is the Expected LRG1 Staining Pattern?
LRG1 is secreted and has no transmembrane segment (UniProt P02750 topology). In paraffin-section IHC, expect distinct plasma positivity, high staining in duodenal Paneth cells, and medium staining in appendix enterocytes, colon goblet cells, and rectal endothelial cells (HPA tissue IHC: Enhanced). Because LRG1 is secreted, tissue protein location can differ from its site of RNA expression (HPA tissue IHC: reliability description).
| Distinct plasma staining, with high staining in duodenal Paneth cells (HPA tissue IHC). | This matches the strongest supplied IHC observations (HPA tissue IHC: Enhanced). Assess plasma and cell staining separately: secretion can make protein location differ from RNA location (HPA tissue IHC: reliability description; UniProt P02750: Secreted). |
| Medium staining in appendix enterocytes, colon goblet cells, or rectal endothelial cells (HPA tissue IHC). | These are reported positive cell populations (HPA tissue IHC: Medium). Compare the named cells within each tissue; the HPA levels describe observed staining and do not establish a universal intensity cutoff (HPA tissue IHC: tissue profile). |
| Strong nuclear staining dominates a section, without the reported plasma or cell pattern (HPA tissue IHC). | Treat this as a possible artefact requiring investigation: LRG1 is annotated as secreted with no transmembrane segment, while the supplied IHC profile emphasizes plasma positivity (UniProt P02750 topology; HPA tissue IHC). |
| Signal appears mainly in an unreported cell population, or in adipocytes listed as not detected (HPA tissue IHC). | Check cell identification, cross-reactivity, and endogenous detection activity (general IHC practice). An unreported cell population alone is not proof of a false positive; the HPA observations are limited to the sampled tissues and cells (HPA tissue IHC). |
| Uniform haze covers cells and empty areas, or duodenal Paneth cells show no signal (HPA tissue IHC: Paneth cells High). | Haze obscures cell-level interpretation and calls for background controls (general IHC practice). Absent signal in the reported high-staining cells calls for a run-control and detection check before interpreting other samples as negative (HPA tissue IHC; general IHC practice). |
💡Expected LRG1 appearanceA convincing positive shows distinct plasma staining, high duodenal Paneth-cell staining, or the specified medium cell staining; widespread nuclear color or uniform haze warrants investigation as possible false signal (HPA tissue IHC: Enhanced; UniProt P02750 topology; general IHC practice).
| Secretion and tissue context (UniProt P02750; HPA tissue IHC). | LRG1 is secreted, and HPA reports distinct plasma positivity; interpret plasma signal alongside the named positive cells (UniProt P02750: Secreted; HPA tissue IHC). Liver-enriched RNA does not, by itself, predict where protein will stain (HPA tissue IHC: RNA specificity and reliability description). |
| Mature chain and glycosylation (UniProt P02750). | The annotated signal peptide spans residues 1–35; the mature chain spans 36–347 and has five annotated glycosylation sites (UniProt P02750). These annotations do not identify the catalog antibody's epitope or establish an antigen-retrieval condition (UniProt P02750 record scope). |
| IHC evidence and antibody choice (HPA antibodies; HPA tissue IHC). | HPA reports Enhanced IHC status for HPA001888 and HPA001889, and Enhanced reliability for the tissue profile (HPA antibodies; HPA tissue IHC). Use that as support for the reported pattern, while checking the IHC-validated antibody's own controls in the current run (general IHC practice). |
| IF/ICC Q: Where is LRG1 localized? (HPA subcellular ICC-IF). | A: HPA approves vesicular localization and lists Hep-G2 among cell lines with ICC-IF images (HPA subcellular ICC-IF). This is an IF/ICC observation; interpret paraffin-section chromogenic IHC using the tissue profile above (HPA tissue IHC; HPA subcellular ICC-IF). |
| Situation | Likely cause | Next action |
|---|---|---|
| No staining in duodenal Paneth cells (HPA tissue IHC: High). | The positive-control run may have failed, or the detection conditions may be unsuitable (general IHC practice). | Check the positive-control section, antibody dilution, retrieval, detection reagents, and counterstain in the IHC workflow (general IHC practice). No LRG1-specific retrieval condition is established by the supplied sources (HPA tissue IHC; UniProt P02750). |
| Plasma stains but the expected cells are hard to judge (HPA tissue IHC). | Prominent plasma signal can complicate cell-level scoring for a secreted protein (HPA tissue IHC: distinct plasma positivity; UniProt P02750: Secreted). | Score plasma and named cell populations separately, using tissue architecture and matched controls to locate cells (HPA tissue IHC; general IHC practice). |
| Diffuse brown haze obscures tissue boundaries (general IHC practice). | Background can arise from insufficient blocking or washing, or from excess antibody or detection reagent (general IHC practice). | Review blocking, washes, dilution, and a control omitting primary antibody; retain conditions that preserve the expected cell pattern (general IHC practice; HPA tissue IHC). |
| Staining appears in a listed negative cell population (HPA tissue IHC). | Cross-reactivity or endogenous detection activity is possible; a single discrepant section cannot establish either cause (general IHC practice). | Check a control omitting primary antibody and review antibody specificity; compare with the exact HPA cell designation, such as adipocytes in adipose tissue (general IHC practice; HPA tissue IHC: Not detected). |
| Nuclear color dominates the slide (general IHC practice). | The dominant pattern conflicts with secreted LRG1 and the reported plasma-centered IHC profile (UniProt P02750 topology; HPA tissue IHC). | Review morphology, counterstain, detection controls, and antibody specificity before scoring the nuclear color as LRG1 (general IHC practice). |
| IF/ICC vesicles seem inconsistent with IHC plasma staining (HPA subcellular ICC-IF; HPA tissue IHC). | The observations come from different preparations: HPA reports vesicles by ICC-IF and distinct plasma positivity by tissue IHC (HPA subcellular ICC-IF; HPA tissue IHC). | Use the tissue IHC observations to judge paraffin sections; consult the separate IF/ICC guide for fluorescence interpretation (HPA tissue IHC; HPA subcellular ICC-IF). |
Experiment evidence
IHC & IF images showing LRG1 staining
A04365-3 · IHCIHC analysis of LRG1 using anti-LRG1 antibody (A04365-3). LRG1 was detected in a paraffin-embedded section of human pancreas cancer tissue.
A04365-3 · IHCIHC analysis of LRG1 using anti-LRG1 antibody (A04365-3). LRG1 was detected in a paraffin-embedded section of rat liver tissue. Heat mediate
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000171236-LRG1/tissue/cerebral+cortex#imid_888968
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000171236-LRG1/tissue/colon#imid_888902
HPA · RectumHuman Protein Atlas IHC, Rectum. Source: https://www.proteinatlas.org/ENSG00000171236-LRG1/tissue/rectum#imid_888862
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000171236-LRG1/tissue/liver#imid_888903
HPA · ICC-IF Hep-G2Human Protein Atlas immunofluorescence, Hep-G2, antibody HPA001889; green = LRG1, blue = nucleus, red = microtubules.
HPA · ICC-IF Hep-G2Human Protein Atlas immunofluorescence, Hep-G2, antibody HPA001889; green = LRG1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for LRG1 IHC & IF
🧪Run duodenum first and assess staining in Paneth cells (HPA: High in duodenal Paneth cells); run adipose tissue as the negative tissue and assess its adipocytes (HPA: Not detected in adipocytes). On the duodenal slide, use neighboring cells without specific signal as internal negatives, verifying their staining rather than assuming they are negative (HPA: High is assigned to Paneth cells).
Positive control tissue: Duodenum (Paneth cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show LRG1 in Hep-G2, with annotated localisation: Vesicles (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control, a species- and class-matched rabbit IgG isotype control, and LRG1 knockout tissue or validated antigen-peptide competition as a biological specificity control (selected IHC caption: rabbit primary antibody). For chromogenic detection, block endogenous peroxidase and inspect background on the duodenal section (selected IHC caption: peroxidase secondary and DAB detection).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported; the selected A04365-3 paraffin-section caption leaves the fixative unreported (selected IHC caption: fixative not stated). Heat retrieval in EDTA at pH 8.0 provides an IHC starting point, but retrieval dependence is unreported (selected IHC caption: heat-mediated EDTA retrieval). Frozen sections are not established as easier; ICC-IF images show vesicular localization in Hep-G2, while secreted, plasma-associated LRG1 can complicate attribution of extracellular signal to a particular duodenal cell (HPA: vesicles in Hep-G2; UniProt P02750: secreted, plasma).
HPA tissue IHC evidence for LRG1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Secreted protein, tissue location of RNA and protein is expected to differ.). 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 |
|---|---|---|---|---|
| Duodenum | Paneth cells | High | Protein (IHC) | HPA → |
| Appendix | Enterocytes | Medium | Protein (IHC) | HPA → |
| Colon | Goblet cells | Medium | Protein (IHC) | HPA → |
| Rectum | Endothelial cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced LRG1 IHC Tips
Troubleshoot LRG1 staining by checking retrieval and controls, then score tissue compartments separately because LRG1 is secreted (UniProt P02750).
What should I change if LRG1 staining is weak in paraffin sections?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 (datasheet A04365-3). In the selected paraffin-section example, the antibody was applied at 1:100 overnight at 4°C, so use those conditions as a documented starting point while evaluating retrieval (caption A04365-3). Compare sections processed together and include a no-primary control to distinguish weak signal from detection background (standard IHC practice). If staining remains weak, adjust heating duration in a small, matched series before trying another retrieval buffer as a fallback (standard IHC practice). Check morphology after heating, since damaged tissue edges can make an apparent gain in staining difficult to interpret (standard IHC practice).
Could fixation explain inconsistent LRG1 staining between paraffin blocks?
Target-specific fixation sensitivity is unknown because the selected paraffin-section caption does not state its fixative (caption A04365-3). Record the fixative, fixation duration and processing history for each block before comparing staining intensity (standard IHC practice). For a controlled comparison, stain matched sections in one run using EDTA retrieval at pH 8.0 and the documented 1:100 primary dilution (caption A04365-3). If blocks differ, compare preserved morphology and staining in the same tissue compartment before attributing the difference to fixation (standard IHC practice). Do not use the reported tissue distribution to estimate fixation tolerance; it establishes no such effect (HPA tissue IHC).
How should I interpret intracellular and extracellular LRG1 staining?
LRG1 is secreted and has no transmembrane segment, so a membrane-bound pattern is not its expected topology (UniProt P02750). Vesicles are an approved intracellular location in the subcellular record, while distinct tissue positivity is reported in plasma (HPA subcellular; HPA tissue IHC). In chromogenic sections, score cellular, vascular or luminal signal separately, and inspect whether extracellular colour follows tissue structure rather than section edges (standard IHC practice). A cytoplasmic signal in the expected cells may be compatible with secretion, but staining alone cannot establish the producing cell (UniProt P02750; HPA tissue IHC). Compare those compartments on matched sections using the same pH 8.0 retrieval conditions (datasheet A04365-3).
Can glycosylation or an unknown epitope change the IHC pattern?
The record lists 5 glycosylation sites, at residues 37, 79, 186, 269 and 325, and no annotated isoforms (UniProt P02750). Its signal peptide spans residues 1–35, leaving residues 36–347 in the annotated mature chain (UniProt P02750). The supplied evidence does not map this antibody’s epitope, so neither glycan sensitivity nor mature-chain recognition can be assigned from the sequence alone (record P02750; caption A04365-3). If staining varies across preparations, compare matched sections with the documented EDTA pH 8.0 retrieval and 1:100 dilution before interpreting an epitope effect (caption A04365-3). An isoform-based explanation would require evidence beyond the supplied record (UniProt P02750).
How can I check an LRG1 pattern by multiplex immunofluorescence?
Use IF as a separate validation experiment: the selected 1:100 paraffin-section example documents chromogenic IHC, not an IF protocol (caption A04365-3). Pair LRG1 with a validated marker of the cell population under study, such as a Paneth-cell marker when examining duodenum, where Paneth-cell positivity is reported (HPA tissue IHC). Choose fluorophores after measuring tissue autofluorescence and include single-channel controls to assess bleed-through (standard IF practice). LRG1 has no transmembrane segment and is reported in vesicles, but the antibody epitope’s membrane accessibility is unknown; titrate permeabilisation against signal and morphology (UniProt P02750; HPA subcellular; standard IF practice). Keep extracellular signal distinct from cellular colocalisation (UniProt P02750; standard IF practice).
How do I reduce diffuse brown staining without losing LRG1 signal?
First compare the stained slide with a no-primary control and inspect whether diffuse colour occurs in plasma-rich spaces, since plasma positivity is reported for LRG1 (HPA tissue IHC; standard IHC practice). The selected paraffin-section example used 10% goat serum blocking, a 1:100 primary dilution and DAB development (caption A04365-3). Check the peroxidase-blocking step and shorten DAB development if the control also turns brown; these are general chromogenic IHC adjustments (standard IHC practice). Retitrate primary concentration with exposure held constant, while retaining EDTA retrieval at pH 8.0 for the initial comparison (datasheet A04365-3; standard IHC practice). Review tissue edges and damaged areas separately before calling diffuse signal specific (standard IHC practice).
What is a defensible way to quantify LRG1 in tissue IHC? ⚠ ANSWER MARKED FOR VERIFICATION
Define the tissue compartment and cell population before scoring, because LRG1 is secreted and tissue RNA and protein locations may differ (UniProt P02750; HPA tissue IHC). For cell-associated staining, report an H-score or the percentage of positive cells with a stated positivity threshold; for spatially restricted deposits, report positive area or density per mm² (standard IHC practice). Normalise each measure to the evaluated viable tissue area or eligible cell count, and apply identical image settings and thresholds across slides (standard IHC practice). Score extracellular or plasma-associated signal separately from cellular staining, rather than combining them into one cell score (HPA tissue IHC; standard IHC practice). Document the pH 8.0 retrieval and staining run used for comparisons (datasheet A04365-3; standard IHC practice).
When is an apparent LRG1-positive area likely to be artefactual?
Compare the pattern with LRG1’s secreted status, reported plasma positivity and approved vesicular location before assigning a cellular source (UniProt P02750; HPA tissue IHC; HPA subcellular). High Paneth-cell positivity in duodenum and undetected adipocyte staining in adipose tissue provide contextual comparisons, but neither alone validates an individual slide (HPA tissue IHC). Suspect an artefact when brown colour concentrates at section edges, necrotic areas or sites of endogenous enzyme activity, especially if the no-primary control shows a similar pattern (standard IHC practice). Check the peroxidase block, tissue preservation and the spatial match to a defined compartment before scoring (standard IHC practice). Report ambiguous extracellular staining separately from confirmed cell-associated staining (UniProt P02750; standard IHC practice).
Boster reagents
Best LRG1 / Leucine-rich alpha-2-glycoprotein IHC Antibodies
The catalog antibody A04365-3 has IHC images from human pancreas cancer, human liver cancer, human liver, and rat liver paraffin sections (catalog IHC captions); no IF image is supplied (catalog IF images).
Real IHC data
Anti-LRG1 Antibody ®
Cat # A04365-3
A04365-3 has IHC images from human pancreas cancer, human liver cancer, human liver, and rat liver paraffin sections (catalog IHC captions). M04365-1 lists human IHC reactivity but has no IHC image in the payload (catalog applications, reactivity, and IHC images).
Which to pick: Choose A04365-3 for paraffin-section tissue IHC because its own captions document those human and rat sections; the fixative is unreported (A04365-3 IHC captions). For IF/ICC, neither SKU has a listed IF application or IF image, so neither has documented IF/ICC validation here (catalog applications and IF images). For cross-species work, A04365-3 is the rabbit polyclonal option with listed human, mouse, and rat reactivity, although its IHC images document human and rat tissue only; M04365-1 is a rabbit monoclonal listed for human reactivity (catalog dilution_raw, reactivity, and IHC captions; M04365-1 catalog host and clone).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P02750 (A2GL_HUMAN, Leucine-rich alpha-2-glycoprotein).
- Human Protein Atlas. LRG1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. LRG1 subcellular location (ICC-IF): Localized to vesicles..
- Human Protein Atlas. LRG1 antibody validation summary (2 antibodies).
- A combination of serum leucine-rich α-2-glycoprotein 1, CA19-9 and interleukin-6 differentiate biliary tract cancer from benign biliary strictures. British journal of cancer 2011 — PMC3241550.
- LRG1 Expression Is Elevated in the Eyes of Patients with Neovascular Age-Related Macular Degeneration. International journal of molecular sciences 2021 — PMC8396268.
- TNF-α-induced LRG1 promotes angiogenesis and mesenchymal stem cell migration in the subchondral bone during osteoarthritis. Cell death & disease 2017 — PMC5386532.
- Gut commensal Alistipes as a potential pathogenic factor in colorectal cancer. Discover oncology 2024 — PMC11436608.
- PubMed PMID:12223515 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
- PubMed PMID:3856868 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for LRG1 (Leucine-rich alpha-2-glycoprotein). Expected localisation Secreted (UniProt); plasma positivity (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A04365-3). Validated IHC antibody: A04365-3 at 2-5 μg/ml recommended; image 1:100 (the product's own IHC validation image is shown). Controls (HPA): positive Duodenum (Paneth cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human pancreas cancer tissue; fixative not specified (datasheet A04365-3); 2. Fixation: Image fixative and duration unreported (datasheet A04365-3); 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 A04365-3); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A04365-3); 8. Primary antibody: Rabbit anti-LRG1, 2-5 μg/ml recommended; image 1:100 (datasheet A04365-3); 9. Primary incubation: Overnight at 4 °C (datasheet A04365-3). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Secretion can separate tissue staining from local RNA expression (HPA tissue IHC); Isoform / epitope: No isoforms annotated; mature chain starts at residue 36 (UniProt); Regulation: Liver-enriched RNA (HPA tissue RNA). Evidence: UniProt P02750, HPA tissue IHC · Enhanced, HPA ICC-IF · vesicles., Datasheet A04365-3, PMC3241550, PMC8396268. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/LRG1/immunohistochemistry-ihc-guide.