This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
ARG1 / Arginase-1 · IHC design guide
Design Immunohistochemistry for ARG1
Plan chromogenic ARG1 IHC in paraffin sections using liver hepatocytes and bone marrow hematopoietic cells as positive references (HPA tissue IHC). This guide covers cytosolic pattern expectations (UniProt), fixation consistency (standard IHC practice), and cell identity when interpreting staining.
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
ARG1 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 | Cytosol; azurophil granules in neutrophils (UniProt) | |
| Staining pattern | Strong hepatocyte and marrow-cell staining; cytosol expected (HPA tissue IHC; UniProt) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A01106) | |
| Positive control | Bone marrow+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 conditions consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Granulocytes also express ARG1; verify immune-cell identity (UniProt) | |
| Regulation | ILC2 expression during lung disease (UniProt) | |
| Isoform / epitope | 3 isoforms; antibody epitope coverage is unspecified (UniProt) |
Section 1
Recommended ARG1 IHC & IF Protocols
The catalog antibody protocol uses heat mediated EDTA retrieval at pH 8.0 (datasheet: A01106). The published IHC protocols below describe paraffin sections (PMC11648120; PMC10371158).
| Sample | Paraffin-embedded human liver cancer tissue; fixative not specified (datasheet A01106) |
| Fixation | Image fixative and duration unreported (datasheet A01106); 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 A01106); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01106) |
| Primary antibody | Rabbit anti-ARG1, 2-5 μg/ml (datasheet A01106) |
| Primary incubation | Overnight at 4 °C (datasheet A01106) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A01106) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | ARG1-positive staining in hematopoietic cells of bone marrow (HPA tissue IHC: High). HPA tissue profile: Selective expression in liver and subsets of bone marrow cells. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval (datasheet: A01106); neither published excerpt specifies a retrieval method (PMC11648120; PMC10371158).
Section 2
What Is the Expected ARG1 Staining Pattern?
ARG1 is a cytosolic protein without a transmembrane segment (UniProt P05089 topology). In paraffin-section IHC, expect strong staining in hepatocytes and subsets of bone-marrow hematopoietic cells (HPA: High in both). HPA describes the tissue pattern as selective for liver and subsets of bone marrow cells, with Enhanced IHC reliability based on consistency between antibody staining and RNA expression (HPA: tissue IHC).
| Strong hepatocyte cytoplasmic staining. | This fits a positive result: hepatocytes stain at a High level (HPA: liver). Assess the distribution across cells and the counterstained tissue architecture (general IHC practice). |
| Strong signal in a subset of bone-marrow hematopoietic cells; occasional granular signal in neutrophils. | HPA reports High staining in bone-marrow hematopoietic cells, without assigning every stained cell a lineage (HPA: bone marrow). ARG1 can localize to neutrophil azurophil granules (UniProt P05089); identify cells by morphology before calling a granular signal specific (general IHC practice). |
| Predominantly nuclear or sharply membrane-bound staining. | That distribution conflicts with the reported cytosolic localization and absence of a transmembrane segment (UniProt P05089 topology). Check morphology and controls before interpreting it as ARG1 (general IHC practice). |
| Prominent signal in cells expected to be negative, or color spread across unrelated structures. | Adipocytes and bronchial respiratory epithelial cells are Not detected in HPA tissue IHC (HPA: adipose tissue; bronchus). In those cells, assess antibody specificity and detection-system background, including endogenous activity where relevant (general IHC practice). |
| Diffuse slide-wide color, or no signal in the liver positive control. | Diffuse color obscures cell-specific scoring; assess blocking, washes and chromogen development (general IHC practice). An unstained liver control conflicts with High hepatocyte staining (HPA: liver); check the IHC run before interpreting a test section as negative (general IHC practice). |
💡Expected ARG1 appearanceCall a result positive when hepatocytes or the expected bone-marrow hematopoietic cells show strong cytoplasmic signal (HPA: High; UniProt P05089 localization); predominant nuclear or membrane signal is discordant (UniProt P05089 topology).
| Cell and tissue context | HPA reports High staining in liver hepatocytes and bone-marrow hematopoietic cells, Medium staining in splenic red-pulp cells and testis preleptotene spermatocytes, and low staining in skin keratinocytes (HPA: tissue IHC). Apply the expected level to the identified cell population, not every cell in the section. |
| Subcellular distribution | Cytosolic ARG1 and neutrophil azurophil-granule localization support cytoplasmic and, in neutrophils, granular interpretation (UniProt P05089). The record gives no transmembrane segment or signal peptide (UniProt P05089 topology and processing). |
| Antibody validation | Five listed antibodies have Enhanced IHC status (HPA: HPA003595, HPA024006, CAB009434, CAB056159, CAB080011). That supports the reported tissue pattern; it does not establish specificity for an unlisted antibody or an unexpected compartment (HPA: antibody validation). |
| Isoforms and processing | Three isoforms are listed, and the annotated chain spans residues 1–322 without a propeptide (UniProt P05089). The supplied evidence does not map antibody epitopes to isoforms, so isoform-specific staining cannot be inferred. |
| Retrieval and fixation | No ARG1-specific retrieval condition or fixation sensitivity is established by these sources (UniProt P05089; HPA: tissue IHC). If optimizing a paraffin IHC run, compare retrieval conditions with a positive control as general IHC practice; do not assign an ARG1-specific fixation effect. |
| IF/ICC applicability | Can IF/ICC confirm this pattern? UniProt reports cytosolic localization, but HPA supplies no main ICC-IF location or cell-line images (UniProt P05089; HPA: subcellular). Treat this as an IHC interpretation guide, not an IF/ICC protocol or independent imaging validation. |
| Situation | Likely cause | Next action |
|---|---|---|
| Liver control has little or no hepatocyte signal. | The result conflicts with High hepatocyte staining (HPA: liver); the failed control alone cannot identify the failed IHC step (general IHC practice). | Check tissue preservation, primary-antibody application, retrieval, detection and chromogen with a parallel control (general IHC practice). Report test-section negatives only after the positive control works. |
| Bone-marrow signal seems absent. | HPA describes selective expression in subsets of bone-marrow cells, although hematopoietic-cell staining is High (HPA: bone marrow). A field without the relevant cells can appear negative. | Review additional fields and cell morphology alongside the liver positive control (HPA: liver; general IHC practice). Avoid assigning ARG1 status to all marrow cells from one field. |
| Nuclei or cell borders dominate the staining. | A predominantly nuclear or membrane-bound pattern is discordant with cytosolic ARG1 and its lack of a transmembrane segment (UniProt P05089 topology). | Compare a negative reagent control and a known-positive tissue; review counterstain and section morphology before scoring the compartment (general IHC practice). |
| Adipocytes or bronchial epithelial cells stain strongly. | These cell populations are Not detected in HPA tissue IHC (HPA: adipose tissue; bronchus). Unexpected color may reflect cross-reactivity or detection-system activity; the image alone cannot distinguish them. | Use appropriate negative controls and check blocking and detection reagents for the chosen chromogenic system (general IHC practice). Reassess cell identity before calling an unexpected positive. |
| Color is diffuse or obscures cell boundaries. | Diffuse background prevents confident cell-level interpretation (general IHC practice); HPA's selective tissue pattern does not support calling uniform slide-wide color specific (HPA: tissue IHC). | Review reagent-only controls, washing, blocking and chromogen development, then compare the repeat section with expected hepatocyte staining (general IHC practice; HPA: liver). |
| Granular staining appears in a suspected neutrophil. | Neutrophil azurophil granules are a reported ARG1 location (UniProt P05089); granular signal alone does not prove the cell's identity or establish antibody specificity (general IHC practice). | Confirm morphology and compare controls and surrounding cells before scoring it; preserve the cytoplasmic hepatocyte pattern as the IHC reference (general IHC practice; HPA: liver). |
Experiment evidence
IHC & IF images showing ARG1 staining
A01106 · IHCIHC analysis of ARG1 using anti-ARG1 antibody (A01106). ARG1 was detected in a paraffin-embedded section of human liver cancer tissue. Heat
A01106 · IHCIHC analysis of ARG1 using anti-ARG1 antibody (A01106). ARG1 was detected in a paraffin-embedded section of mouse liver tissue. Heat mediate
M01106-5 · IHCHuman hepatocellular carcinoma was stained with anti-Arginase-1 rabbit antibody
M01106-5 · IHCHuman liver was stained with anti-Arginase-1 rabbit antibody
M01106-2 · IHCImmunohistochemical analysis of paraffin-embedded human liver, using Liver Arginase Antibody.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000118520-ARG1/tissue/cerebral+cortex#imid_21157683
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000118520-ARG1/tissue/colon#imid_21157601
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000118520-ARG1/tissue/liver#imid_21157602
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000118520-ARG1/tissue/kidney#imid_21157611
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for ARG1 IHC & IF
🧪Run liver first: hepatocytes should stain for ARG1 (HPA: High in hepatocytes). Use adipose tissue as the negative tissue, with adipocytes expected to be unstained (HPA: Not detected in adipocytes); on the liver slide, assess morphologically distinct non-hepatocyte areas as an internal background reference without assuming every such cell is ARG1-negative.
Positive control tissue: Bone marrow (Hematopoietic cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for ARG1; derive a cell-line control from the positive tissue's cell type (Hematopoietic cells) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control, a concentration-matched rabbit IgG isotype control matched to the primary antibody’s clonality (selected A01106 caption: rabbit primary antibody), and a validated ARG1-knockout biological negative. For liver sections, block endogenous peroxidase and check for endogenous biotin background when using the caption’s biotin-based, DAB detection method (selected A01106 caption: SABC with DAB; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the fixative is unreported in the selected A01106 paraffin-section caption. Start with heat-mediated EDTA retrieval at pH 8.0 as used in that caption; retrieval dependence has not been established (selected A01106 caption: EDTA retrieval). The supplied evidence does not establish whether frozen sections or IF/ICC are easier (HPA subcellular: no ICC-IF images); endogenous biotin can cause liver background with the caption’s SABC detection method (selected A01106 caption: SABC; standard IHC practice).
HPA tissue IHC evidence for ARG1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High consistency between antibody staining and RNA expression data.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Liver | Hepatocytes | High | Protein (IHC) | HPA → |
| Spleen | Cells in red pulp | Medium | Protein (IHC) | HPA → |
| Testis | Preleptotene spermatocytes | 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 → |
| Appendix | Glandular 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 ARG1 IHC Tips
Troubleshoot ARG1 staining in paraffin sections by checking retrieval, cellular localisation, controls and scoring before interpreting chromogenic signal.
How should I retrieve ARG1 when staining is weak in paraffin sections?
Start with heat-mediated retrieval in EDTA at pH 8.0 (datasheet A01106). The selected paraffin-section example used this retrieval before incubating with 2 μg/ml catalog antibody overnight at 4°C (datasheet A01106). If signal is weak, confirm that sections received consistent heating and cooling, then compare a longer retrieval interval on matched sections while holding antibody concentration and detection constant (standard IHC practice). Include liver hepatocytes as a positive reference and an appropriate negative control, since hepatocyte staining is high whereas adipocyte staining was not detected in the tissue survey (HPA tissue IHC). Excessive retrieval can damage section morphology, so assess staining and tissue integrity together (standard IHC practice).
Could fixation explain variable ARG1 staining between paraffin blocks?
Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative or fixation duration (datasheet A01106). Record each block’s fixative, time before fixation and fixation duration, then compare sections processed with the same retrieval and detection conditions (standard IHC practice). Keep heat-mediated EDTA retrieval at pH 8.0 as the initial condition because it was used for this antibody in the selected tissue example (datasheet A01106). Use a liver hepatocyte control in each run to distinguish a block-specific loss of signal from a run-wide problem (HPA tissue IHC; standard IHC practice). Do not assign a particular fixation effect to ARG1 without matched experimental evidence.
Where should ARG1 staining appear, and how should punctate signal be assessed?
Expect predominantly cytoplasmic staining because ARG1 is annotated in the cytosol and has no transmembrane segment (UniProt P05089). Punctate cytoplasmic signal can be plausible in neutrophils, where ARG1 is reported in azurophil granules (UniProt P05089). Evaluate that pattern within identifiable cells and alongside a 2 μg/ml antibody condition matching the selected paraffin-section example, rather than treating isolated extracellular deposits as localisation evidence (datasheet A01106; standard IHC practice). High hepatocyte and bone-marrow hematopoietic-cell staining provide tissue context, although cell identity still requires morphology or a companion marker (HPA tissue IHC; standard IHC practice). Predominantly nuclear or membrane-only staining warrants review of controls and detection background because those compartments are not the annotated ARG1 location (UniProt P05089).
Can the catalog antibody distinguish ARG1 isoforms or modified epitopes in tissue?
The record lists 3 ARG1 isoforms, but the supplied antibody evidence does not map its epitope or establish isoform selectivity (UniProt P05089; datasheet A01106). The annotated main chain spans residues 1–322, with modified residues including phosphoserine at 62, 72 and 163 (UniProt P05089). Do not interpret a staining difference as an isoform or phosphorylation difference without epitope information and independently validated controls (standard IHC practice). Compare candidate tissues under identical EDTA pH 8.0 retrieval and detection conditions, then report the result as ARG1 immunoreactivity (datasheet A01106; standard IHC practice). If an epitope-specific conclusion matters, obtain direct antibody validation for that claim before scoring sections.
How should I adapt ARG1 localisation checks to multiplex immunofluorescence?
The selected antibody example documents chromogenic staining of a paraffin section; it does not establish an IF/ICC protocol (datasheet A01106). For an exploratory IF assay, pair ARG1 with a validated marker of the cell population under study, such as a hepatocyte or neutrophil marker, and check whether signal falls within the expected cytoplasmic compartment (HPA tissue IHC; UniProt P05089; standard IF practice). Choose fluorophores after examining tissue autofluorescence and reserve a spectrally clear channel for the weaker signal (standard IF practice). Because ARG1 has no transmembrane segment and is cytosolic, include a controlled permeabilisation comparison to expose intracellular epitopes (UniProt P05089; standard IF practice). Run single-stain and secondary-only controls before interpreting colocalisation (standard IF practice).
How can I reduce diffuse brown staining while preserving ARG1 signal?
The selected tissue example used 10% goat serum before 2 μg/ml rabbit antibody overnight at 4°C, followed by biotinylated secondary antibody and SABC–DAB detection (datasheet A01106). First compare a no-primary control with the stained section and verify that blocking, washes and DAB development are consistent across slides (standard IHC practice). Include a peroxidase block for chromogenic detection, and consider a biotin-blocking or biotin-free detection comparison if the biotin-based system produces background (standard IHC practice). Titrate primary antibody on matched sections while retaining EDTA pH 8.0 retrieval and a liver positive control (datasheet A01106; HPA tissue IHC). Judge improvement by cleaner cell boundaries and retained hepatocyte staining, not by a paler slide alone (HPA tissue IHC; standard IHC practice).
What is a defensible way to quantify ARG1-positive cells in sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the region and cell population before scoring, since ARG1 is high in hepatocytes and bone-marrow hematopoietic cells but only medium in splenic red-pulp cells in the tissue survey (HPA tissue IHC). For hepatocytes, report the percentage of positive viable cells or an H-score using intensity categories 0–3 multiplied by each category’s cell percentage (standard IHC practice). For dispersed immune cells, report positive-cell density per mm² of viable tissue and, where possible, the positive fraction among the relevant identified cells (standard IHC practice). Apply one threshold and identical imaging settings across comparison groups, and exclude folds, necrosis and section edges using predefined criteria (standard IHC practice). Normalise counts to the sampled viable area or the target-cell denominator, and include a run-level liver control (HPA tissue IHC; standard IHC practice).
When is ARG1 staining credible rather than a detection artefact?
Credible staining should occupy the cytoplasm of morphologically identified cells; neutrophil granules are also an annotated ARG1 location (UniProt P05089). High hepatocyte and bone-marrow hematopoietic-cell staining is consistent with the tissue survey, while an unexpected cell population needs independent identity and antibody controls (HPA tissue IHC; standard IHC practice). Compare signal with a no-primary section to identify endogenous peroxidase or detection-system background, especially before accepting diffuse DAB deposits (standard IHC practice). Treat strong section-edge staining, necrotic debris and predominantly nuclear or membrane-only signal as reasons to recheck staining and morphology (UniProt P05089; standard IHC practice). A clean positive control and reproducible staining within viable cells support interpretation more strongly than intensity in a single field (standard IHC practice).
Boster reagents
Best ARG1 / Arginase-1 IHC Antibodies
These anti-ARG1 antibodies have IHC images from human, mouse, and rat tissues (IHC captions: A01106, M01106-5, M01106-2); two also list IF applications (catalog: M01106-5, M01106-2).
Real IHC data
Anti-liver Arginase/ARG1 Antibody ®
Cat # A01106
Real IHC data
Anti-Arginase-1 Rabbit Monoclonal Antibody
Cat # M01106-5
Real IHC data
Anti-Liver Arginase ARG1 Rabbit Monoclonal Antibody
Cat # M01106-2
A01106 shows paraffin-section IHC in human liver cancer and mouse and rat liver (IHC captions: A01106). M01106-5 shows IHC in human hepatocellular carcinoma and human, mouse, and rat liver, while M01106-2 shows paraffin-section IHC in human liver (IHC captions: M01106-5, M01106-2).
Which to pick: For paraffin-section IHC, A01106 has a documented EDTA pH 8.0 retrieval and DAB workflow at 2 μg/ml (IHC caption: A01106); M01106-2 is a human-reactive monoclonal with a paraffin-section image, but its fixative is unreported (catalog: M01106-2 reactivity and clonality; IHC caption: M01106-2). For IF/ICC, M01106-2 lists both applications, while M01106-5 lists IF only; neither has an IF image in the payload (catalog: applications and IF image alts). For cross-species tissue IHC, A01106 has human, mouse, and rat paraffin-section images and lists monkey reactivity; M01106-5 has human, mouse, and rat IHC images and is monoclonal (IHC captions: A01106, M01106-5; catalog: reactivity and clonality).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P05089 (ARGI1_HUMAN, Arginase-1).
- Human Protein Atlas. ARG1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. ARG1 subcellular location (ICC-IF): Highest expression in Hep-G2: 4.5 nTPM.
- Human Protein Atlas. ARG1 antibody validation summary (5 antibodies).
- Human umbilical cord mesenchymal stem cells alleviate hypoxic-ischemia-induced white-matter injury in neonatal rats by regulating polarization of microglia. Scientific reports 2026 — PMC13066634.
- ARG1 Is a Potential Prognostic Marker in Metastatic Endometrial Cancer. Reproductive sciences (Thousand Oaks, Calif.) 2024 — PMC11648120.
- ARG1 is a potential prognostic marker in metastatic and recurrent endometrial cancer. Research square 2023 — PMC10371158.
- ARG1 Inhibition after Neonatal Hypoxic-Ischemic Brain Injury. Developmental neuroscience 2026 — PMC13044354.
- PubMed PMID:3540966 — UniProt-cited evidence.
- PubMed PMID:3174433 — UniProt-cited evidence.
- PubMed PMID:14574404 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for ARG1 (Arginase-1). Expected localisation Cytosol; azurophil granules in neutrophils (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A01106). Validated IHC antibody: A01106 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Bone marrow (Hematopoietic cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human liver cancer tissue; fixative not specified (datasheet A01106); 2. Fixation: Image fixative and duration unreported (datasheet A01106); 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 A01106); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01106); 8. Primary antibody: Rabbit anti-ARG1, 2-5 μg/ml (datasheet A01106); 9. Primary incubation: Overnight at 4 °C (datasheet A01106). Watch for: Fixation: Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific); Caveat: Granulocytes also express ARG1; verify immune-cell identity (UniProt); Isoform / epitope: 3 isoforms; antibody epitope coverage is unspecified (UniProt); Regulation: ILC2 expression during lung disease (UniProt). Evidence: UniProt P05089, HPA tissue IHC · Enhanced, HPA cell-line RNA · Highest expression in Hep-G2: 4.5 nTPM, Datasheet A01106, PMC11648120, PMC10371158. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/ARG1/immunohistochemistry-ihc-guide.