This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
SERPINA3 / Alpha-1-antichymotrypsin · IHC design guide
Design Immunohistochemistry for SERPINA3
Plan chromogenic SERPINA3 IHC in paraffin sections using cervical glandular cells as a high-staining reference (HPA tissue IHC). Interpret extracellular deposits and limited cytoplasmic staining in light of secretion and inflammation-linked abundance (HPA tissue IHC; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SERPINA3 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 | Extracellular deposits and cytoplasm in a few cell types (HPA tissue IHC) | |
| Staining pattern | Extracellular deposits with cytoplasmic staining in a few cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet PA2217) | |
| Positive control | Cerebellum+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 paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | Secretion can separate tissue RNA from protein staining (HPA tissue IHC) | |
| Regulation | Rises during inflammation or infection (UniProt) | |
| Isoform / epitope | 3 isoforms; mature N terminus varies (UniProt) |
Section 1
Recommended SERPINA3 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by four published SERPINA3 IHC protocols (PMC9592916; PMC13094457; PMC5403010; PMC12808515).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet PA2217); 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 PA2217); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet PA2217) |
| Primary antibody | Rabbit anti-SERPINA3, 0.5-1μg/ml (datasheet PA2217) |
| Primary incubation | Overnight at 4 °C (datasheet PA2217) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet PA2217) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SERPINA3-positive staining in granular cells - nucleus of cerebellum (HPA tissue IHC: High). HPA tissue profile: Positivity in extracellular deposits and cytoplasmic expression in a few cell types. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 (datasheet: PA2217); a published lung-tissue protocol uses citrate at pH 6.0 (PMC13094457).
Section 2
What Is the Expected SERPINA3 Staining Pattern?
SERPINA3 is secreted and has no transmembrane segment (UniProt P01011). In paraffin-section IHC, expect extracellular deposits and cytoplasmic staining in selected cells (HPA tissue IHC: Enhanced). Cervical glandular cells stain strongly, while hepatocyte staining is low in the HPA survey (HPA: High in cervical glandular cells; Low in hepatocytes).
| Strong staining in cervical glandular cells, with some extracellular deposits. | This fits the reported pattern (HPA: High in cervical glandular cells; extracellular deposits). Score cellular staining and deposits separately because secreted SERPINA3 can be present outside its producing cells (UniProt P01011: Secreted). |
| Staining is confined to an unexpected compartment in a cell type otherwise reported as positive. | Check for artefact and compare the cell type with HPA before interpreting it (HPA tissue IHC: cytoplasmic expression in a few cell types). A blanket rule that nuclear staining is false would be misleading: HPA reports High nuclear staining in cerebellar granular cells. |
| Strong staining appears in cells reported as undetected, such as adipocytes. | Treat the result as unconfirmed; cross-reactivity or endogenous detection activity is possible (HPA: adipocytes Not detected; standard IHC practice). Review the cell identity, detection controls, and whether the signal follows tissue structure before assigning it to SERPINA3. |
| Broad, fairly uniform color covers cells and extracellular spaces. | This differs from the selected-cell and deposit pattern (HPA tissue IHC: positivity in extracellular deposits and cytoplasmic expression in a few cell types). Background from the detection workflow is possible; compare a control section processed without primary antibody (standard IHC practice). |
| No staining appears in cervical glandular cells on a test section. | The result needs a control and a check of section quality, retrieval, antibody dilution, and detection (HPA: High in cervical glandular cells; standard IHC practice). An absent signal alone cannot establish that the specimen lacks SERPINA3. |
💡Expected SERPINA3 appearanceA convincing positive result has strong cervical glandular-cell staining with possible extracellular deposits (HPA: High in cervical glandular cells; extracellular deposits); widespread uniform color or strong staining in HPA-undetected adipocytes warrants investigation (HPA: adipocytes Not detected; standard IHC practice).
| Secretion and tissue location (UniProt P01011: Secreted; HPA tissue IHC: extracellular deposits). | Interpret deposits alongside stained cells; extracellular signal need not identify the cell that made the protein (UniProt P01011: Secreted). |
| Cell-specific reference pattern (HPA tissue IHC: Enhanced). | Use the named cell population, not the organ alone, as the comparison: cervical glandular cells are High, whereas hepatocytes are Low (HPA tissue IHC). |
| Processing and glycosylation (UniProt P01011: signal peptide 1–23; six glycosylation sites). | The mature annotated chains begin at residue 24 or 26 (UniProt P01011). Epitope accessibility in paraffin sections cannot be inferred without the antibody's epitope information. |
| Isoforms and antibody validation (UniProt P01011: three isoforms; HPA antibodies: IHC Enhanced or Supported). | The supplied record does not show which isoforms each antibody recognizes (UniProt P01011; HPA antibodies). Compare staining with the chosen antibody's IHC validation. |
| IF/ICC Q: Is a subcellular IF pattern established? (HPA subcellular: Secreted). | A: HPA gives no main intracellular location or cell-line ICC-IF images, and the listed antibodies have no ICC status (HPA subcellular; HPA antibodies). Do not assign a validated organelle pattern. |
| Situation | Likely cause | Next action |
|---|---|---|
| Cervical glandular cells lack signal (HPA: High). | The staining run may have failed, or the tested section may differ from the HPA reference (standard IHC practice; HPA tissue IHC). | Run an appropriate known-positive section alongside it; review tissue preservation, retrieval, antibody dilution, and detection before interpreting absence (standard IHC practice). |
| The whole section is diffusely colored (HPA tissue IHC: selected cells and deposits). | Nonspecific binding or detection background may obscure the reported pattern (standard IHC practice; HPA tissue IHC). | Compare a section processed without primary antibody; review blocking, washes, detection conditions, and exposure time (standard IHC practice). |
| Strong color appears in adipocytes (HPA: Not detected). | Cross-reactivity or endogenous detection activity is possible; the HPA finding alone cannot identify the cause (HPA: adipocytes Not detected; standard IHC practice). | Check the no-primary control and, where available, an independently validated antibody; assess whether color follows cell structures (standard IHC practice). |
| Only extracellular staining is visible (HPA tissue IHC: extracellular deposits). | Secreted protein can accumulate away from stained cells, but deposits alone do not establish their source (UniProt P01011: Secreted; HPA tissue IHC). | Record deposits separately and examine expected cellular staining in a suitable control section (HPA: High in cervical glandular cells; standard IHC practice). |
| Nuclear staining seems inconsistent with secretion (UniProt P01011: Secreted). | Compartment expectations vary by reported cell type; HPA specifically records nuclear signal in cerebellar granular cells (HPA: High in granular-cell nuclei). | Confirm the cell type, inspect the no-primary control, and compare the finding with HPA's tissue-specific pattern before calling it artefact (HPA tissue IHC; standard IHC practice). |
| A low-staining liver section is used to judge a failed run (HPA: Low in hepatocytes). | Low hepatocyte staining is the HPA protein-IHC observation, despite liver synthesis and liver-enriched RNA (HPA tissue IHC; UniProt P01011: synthesized in liver). | Use a clearly stained reference such as cervical glandular cells to assess run performance; do not require strong hepatocyte staining (HPA: High in cervical glandular cells; Low in hepatocytes). |
Experiment evidence
IHC & IF images showing SERPINA3 staining
PA2217 · IHCAnti-AACT/SERPINA3 antibody, PA2217, IHC(P) IHC(P): Human Liver Cancer Tissue
PA2217 · IHCIHC analysis of Alpha Antichymotrypsin/SERPINA3 using anti-Alpha Antichymotrypsin/SERPINA3 antibody (PA2217). Alpha Antichymotrypsin/SERPINA
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000196136-SERPINA3/tissue/cerebral+cortex#imid_20534339
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000196136-SERPINA3/tissue/colon#imid_20532673
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000196136-SERPINA3/tissue/liver#imid_20532666
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000196136-SERPINA3/tissue/kidney#imid_20532683
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SERPINA3 IHC & IF
🧪Run cervix first and look for staining in glandular cells (HPA: High in cervix glandular cells). Use adipose tissue as the negative comparator (HPA: Not detected in adipocytes); on the cervix slide, treat non-glandular cells as internal negatives only if they remain at background.
Positive control tissue: Cerebellum (Granular cells - nucleus, 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 SERPINA3; derive a cell-line control from the positive tissue's cell type (Granular cells - nucleus) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary (secondary-only) control and a host-species- and isotype-matched control for a monoclonal primary, or species-matched nonimmune IgG for a polyclonal primary. Where available, use SERPINA3 knockout tissue or a validated peptide block as a biological specificity control; for chromogenic detection, block endogenous peroxidase and check the no-primary slide for residual signal.
⚠️Feasibility: A target-specific fixation window and retrieval dependency are unreported in the supplied evidence; the selected PA2217 paraffin-section caption also leaves the fixative unreported (caption: IHC(P) on human liver cancer tissue). The supplied evidence does not establish that frozen sections or IF are easier, and HPA lists no cell lines with ICC-IF images (HPA: subcellular record). Because SERPINA3 is secreted and found in plasma, assess extracellular or vascular staining separately from glandular-cell staining (UniProt P01011: secreted; tissue specificity: plasma).
HPA tissue IHC evidence for SERPINA3
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — At least one protein variant secreted, tissue location of RNA and protein might differ and correlation is complex.). 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 |
|---|---|---|---|---|
| Cerebellum | Granular cells - nucleus | High | Protein (IHC) | HPA → |
| Cervix | Glandular cells | High | Protein (IHC) | HPA → |
| Breast | Glandular cells | Medium | Protein (IHC) | HPA → |
| Kidney | Proximal tubules (cell body) | Medium | Protein (IHC) | HPA → |
| Placenta | Trophoblastic cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Appendix | Endocrine cells | Not detected | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Cerebral cortex | Endothelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SERPINA3 IHC Tips
Troubleshoot SERPINA3 staining in paraffin sections by checking retrieval, tissue context, secreted protein localisation and the controls used for scoring.
What retrieval should I try when SERPINA3 staining is weak in paraffin sections?
Use heat-mediated HIER in EDTA pH 8.0 for PA2217 paraffin-section IHC (datasheet PA2217). Keep heating and cooling conditions consistent across sections, then compare signal with a matched no-primary control (standard IHC practice). If staining remains weak, trial a shorter or longer heating interval on adjacent sections before testing another retrieval buffer as a fallback (standard IHC practice). Score specific cellular or extracellular staining separately from diffuse background, because SERPINA3 is secreted and tissue deposits can be positive (UniProt P01011 localisation; HPA tissue IHC profile).
How should I troubleshoot fixation-related loss of SERPINA3 staining?
The PA2217 tissue caption identifies paraffin-section staining but does not report the fixative, so target-specific fixation sensitivity is unknown (PA2217 tissue-IHC caption). Record the specimen fixative, fixation duration and processing history before comparing staining across cases (standard IHC practice). If archived sections differ in fixation history, stain adjacent sections in the same run and assess morphology alongside signal rather than assigning a weak result to SERPINA3 chemistry (standard IHC practice). Use a documented positive control and a no-primary control to distinguish loss of interpretable staining from excess detection background (standard IHC practice); the caption alone cannot establish an optimal fixation time (PA2217 tissue-IHC caption).
Should SERPINA3 staining be cytoplasmic, extracellular or nuclear?
Expect an interpretable mixture of extracellular deposits and cytoplasmic staining in selected cell types, consistent with the tissue IHC profile (HPA tissue IHC profile). SERPINA3 is secreted and has a signal peptide at residues 1–23 with no transmembrane segment, so a sharp membrane-only pattern warrants control review (UniProt P01011 localisation and topology). HPA also reports high nuclear staining in cerebellar granular cells; evaluate that observation in its tissue context rather than applying it to every section (HPA cerebellum tissue IHC). Compare stained structures with the counterstain and a no-primary section, and record cellular and extracellular compartments separately (standard IHC practice).
Could isoforms or processing explain different SERPINA3 staining patterns?
SERPINA3 has 3 annotated isoforms and processed chains beginning at residues 24 or 26 (UniProt P01011 isoforms and processing). It also has 6 annotated glycosylation sites, which makes epitope accessibility a reasonable variable to examine without assuming a specific staining effect (UniProt P01011 glycosylation; standard IHC practice). Check the catalog antibody’s stated immunogen or mapped epitope before attributing a pattern to one isoform or processed chain (standard IHC practice). If the epitope is unspecified, describe the result as antibody-detected SERPINA3 staining and compare serial sections under identical retrieval and detection conditions (standard IHC practice).
How should I assess SERPINA3 in a multiplex IF experiment?
This page’s product evidence is paraffin-section IHC in human liver cancer tissue; the caption does not establish an IF protocol or fixative (PA2217 tissue-IHC caption). For exploratory IF, pair SERPINA3 with a validated marker for the expected cell type and inspect each channel separately before interpreting overlap (standard IF practice). Choose fluorophores away from the specimen’s strongest autofluorescence and include single-label and no-primary controls to check bleed-through and background (standard IF practice). Because SERPINA3 is secreted and lacks a transmembrane segment, optimise permeabilisation for the antibody’s accessible intracellular epitope while preserving extracellular signal; an unspecified epitope leaves that choice empirical (UniProt P01011 localisation and topology; standard IF practice).
How can I reduce diffuse brown background without losing extracellular SERPINA3 signal?
First compare the section with a no-primary control to identify detection-system background, and inspect whether brown material follows tissue edges or damaged areas (standard IHC practice). For chromogenic peroxidase detection, use an endogenous-peroxidase block, appropriate protein blocking and thorough washes before adjusting antibody concentration (standard IHC practice). Titrate the primary antibody and shorten chromogen development on adjacent sections, keeping the positive control in every run (standard IHC practice). Do not discard all diffuse extracellular staining as background: extracellular deposits are part of the reported tissue profile, and SERPINA3 is secreted (HPA tissue IHC profile; UniProt P01011 localisation).
How should I score SERPINA3 when both cells and extracellular deposits stain? ⚠ ANSWER MARKED FOR VERIFICATION
Define regions of interest on the counterstained section and exclude folds, tissue loss and overtly damaged areas before scoring (standard IHC practice). For cellular staining, report the percentage of positive cells and an intensity-weighted H-score within a specified cell population; keep extracellular deposits in a separate measurement (standard IHC practice; HPA tissue IHC profile). Quantify deposits as positive area or optical density per mm² of analysable tissue, with the same threshold and imaging settings across cases (standard IHC practice). Normalise cellular results to the counted cells and deposit results to tissue area, because secreted SERPINA3 can appear outside cells (standard IHC practice; UniProt P01011 localisation).
What distinguishes a convincing SERPINA3 positive from a staining artefact?
A convincing result has reproducible staining in anatomically plausible cells or extracellular deposits, with little corresponding signal in the no-primary control (HPA tissue IHC profile; standard IHC practice). Compare cell identity and compartment against the section: HPA reports high glandular-cell staining in cervix and low hepatocyte staining in liver, so intensity expectations are context dependent (HPA tissue IHC). Treat a uniform membrane-only rim cautiously because SERPINA3 is secreted and has no transmembrane segment (UniProt P01011 localisation and topology). Review edge staining, necrotic regions and residual endogenous-peroxidase colour against morphology and controls before calling any brown deposit positive (standard IHC practice).
Boster reagents
Best SERPINA3 / Alpha-1-antichymotrypsin IHC Antibodies
The catalog covers human IHC and IF/ICC (catalog applications and reactivity). Real IHC images show paraffin sections of human liver and liver cancer (PA2217 image captions).
Real IHC data
Anti-AACT/SERPINA3 Antibody ®
Cat # PA2217
The PA2217 card renders with IHC data from a paraffin section of human liver cancer (PA2217 image caption). A second caption documents IHC in a paraffin section of human liver (PA2217 image caption).
Which to pick: Choose PA2217 for human tissue IHC: its images document paraffin sections, and the fixative is unreported (PA2217 image captions). For human IF/ICC, M02312 is a rabbit monoclonal listed for those applications, with no IF image supplied (M02312 catalog). Neither SKU lists cross-species reactivity; both list Human only (catalog reactivity).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P01011 (AACT_HUMAN, Alpha-1-antichymotrypsin).
- Human Protein Atlas. SERPINA3 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. SERPINA3 subcellular location (ICC-IF): Secreted.
- Human Protein Atlas. SERPINA3 antibody validation summary (3 antibodies).
- Immune-related SERPINA3 as a biomarker involved in diabetic nephropathy renal tubular injury. Frontiers in immunology 2022 — PMC9592916.
- A Potential Novel Molecular Interaction in Bronchiolitis Obliterans Syndrome in Lung Transplantation Patients: The Role of SERPINA3 and Osteoprotegerin. FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2026 — PMC13094457.
- Serpin peptidase inhibitor, clade A member 3 (SERPINA3), is overexpressed in glioma and associated with poor prognosis in glioma patients. OncoTargets and therapy 2017 — PMC5403010.
- SERPINA3 facilitates malignant progression and remodels tumor immune microenvironment in glioma. Biochemistry and biophysics reports 2026 — PMC12808515.
- PubMed PMID:6606438 — UniProt-cited evidence.
- PubMed PMID:8244391 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SERPINA3 (Alpha-1-antichymotrypsin). Expected localisation Extracellular deposits and cytoplasm in a few cell types (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet PA2217). Validated IHC antibody: PA2217 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Cerebellum (Granular cells - nucleus); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Tissue sections; selected-image fixative not specified (standard IHC workflow); 2. Fixation: Image fixative and duration unreported (datasheet PA2217); 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 PA2217); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet PA2217); 8. Primary antibody: Rabbit anti-SERPINA3, 0.5-1μg/ml (datasheet PA2217); 9. Primary incubation: Overnight at 4 °C (datasheet PA2217). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Secretion can separate tissue RNA from protein staining (HPA tissue IHC); Isoform / epitope: 3 isoforms; mature N terminus varies (UniProt); Regulation: Rises during inflammation or infection (UniProt). Evidence: UniProt P01011, HPA tissue IHC · Enhanced, HPA ICC-IF · Secreted, Datasheet PA2217, PMC9592916, PMC13094457. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SERPINA3/immunohistochemistry-ihc-guide.