This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
GSTA1 / Glutathione S-transferase A1 · IHC design guide
Design Immunohistochemistry for GSTA1
Plan chromogenic IHC for GSTA1 in paraffin sections using hepatocytes and kidney tubule cells as positive references (HPA tissue IHC). Interpret staining cautiously because the catalog antibody also recognizes GSTA2–5 (datasheet A01462-1).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
GSTA1 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 staining in several tissues (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining in hepatocytes and kidney tubule cells (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6 HIER, heat-mediated (datasheet A01462-1) | |
| Positive control | Adrenal gland+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 sections (standard IHC practice; not target-specific) | |
| Caveat | The antibody also recognizes GSTA2–5 (datasheet A01462-1) | |
| Regulation | Tissue-specific expression in liver (UniProt) | |
| Isoform / epitope | No annotated isoforms; N-terminal processing removes residue 1 (UniProt) |
Section 1
Recommended GSTA1 IHC & IF Protocols
The catalog antibody protocol (datasheet: A01462-1) is followed by published GSTA1 IHC protocols for sow oviduct (PMC4476686), lung adenocarcinoma (PMC12997922), and hepatocellular carcinoma (PMC6930411).
| Sample | Paraffin-embedded human lung cancer tissues; fixative not specified (datasheet A01462-1) |
| Fixation | Image fixative and duration unreported (datasheet A01462-1); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Citrate pH 6, 20 min (datasheet A01462-1) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01462-1) |
| Primary antibody | Rabbit anti-GSTA1, 1μg/ml (datasheet A01462-1) |
| Primary incubation | Overnight at 4 °C (datasheet A01462-1) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A01462-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | GSTA1-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Distinct cytoplasmic expression in several tissues including liver, kidney and adrenal gland. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated citrate retrieval at pH 6 (datasheet: A01462-1); consider microwave EDTA at pH 9 when adapting the lung adenocarcinoma protocol (PMC12997922).
Section 2
What Is the Expected GSTA1 Staining Pattern?
GSTA1 is a cytoplasmic protein with no transmembrane segment (UniProt P08263). In paraffin sections, expect cytoplasmic staining in hepatocytes and kidney tubular cells, with high staining also reported in adrenal glandular cells, duodenal endocrine cells, gallbladder glandular cells and testicular Leydig cells (HPA: High). HPA rates the tissue pattern Supported, with medium consistency between antibody staining and RNA expression; its antibodies may also detect proteins from more than one gene (HPA: tissue IHC).
| Hepatocytes or kidney tubular cells show strong cytoplasmic chromogen, while nuclei remain visually distinct. | This matches GSTA1 localisation (UniProt P08263: Cytoplasm) and two high-staining reference populations (HPA: High in hepatocytes and kidney tubular cells). Score the relevant cells and compartment; overall section darkness alone does not establish a correct pattern (general IHC practice). |
| The dominant signal appears confined to nuclei or outlines cell membranes, with little cytoplasmic staining. | That distribution conflicts with the reported cytoplasmic localisation and absence of a transmembrane segment (UniProt P08263). Treat it as an unexpected pattern, check the counterstain and detection controls, and avoid assigning it to GSTA1 without independent support (general IHC practice). |
| Strong colour appears mainly in adipocytes or marrow hematopoietic cells instead of expected positive populations. | Those populations are reported as not detected, whereas hepatocytes and kidney tubular cells are High (HPA: tissue IHC). Consider nonspecific antibody binding or endogenous detection activity (general IHC practice); HPA cautions that its antibodies can target proteins from more than one gene (HPA: tissue IHC). |
| Weak, fairly uniform colour covers cells, extracellular areas or much of the section. | Diffuse colour does not reproduce the distinct cytoplasmic pattern reported across selected tissues (HPA: tissue IHC). Assess reagent-only and tissue controls, washing and blocking before interpreting weak colour as cellular staining (general IHC practice). |
| Hepatocytes show no discernible cytoplasmic signal in a run intended to detect GSTA1. | Liver hepatocytes are a high-staining reference population (HPA: High in hepatocytes; UniProt P08263: liver tissue specificity). Check section quality and the IHC detection run before calling the sample negative (general IHC practice). HPA's Supported rating does not guarantee every antibody will perform identically (HPA: tissue IHC). |
💡Expected GSTA1 appearanceA convincing positive is strong cytoplasmic staining in hepatocytes or kidney tubular cells (HPA: High; UniProt P08263: Cytoplasm); dominant nuclear, membranous or uniform section-wide colour is an unexpected pattern requiring control review (general IHC practice).
| Which compartment should guide scoring? | Use cellular cytoplasm as the expected compartment (UniProt P08263: Cytoplasm; HPA: distinct cytoplasmic expression). A membrane-only interpretation has no support from the reported topology (UniProt P08263: no transmembrane segment). |
| Which tissues offer the clearest comparisons? | Liver hepatocytes and kidney tubular cells are High, while adipocytes and marrow hematopoietic cells are Not detected (HPA: tissue IHC). These are comparative observations, not universal positive or negative guarantees for every section (HPA: Supported, medium consistency). |
| How specific is the reported pattern? | HPA labels the tissue result Supported but warns that antibodies may target proteins from more than one gene (HPA: tissue IHC). Its listed antibodies HPA004342, HPA048934 and HPA053817 each have Supported IHC status (HPA: antibody validation); staining alone cannot resolve cross-reactivity. |
| Does protein processing imply another staining compartment? | UniProt reports full-length and N-terminally processed chains, no signal peptide or propeptide, and no listed isoforms (UniProt P08263: processing and isoforms). These annotations provide no basis for predicting secreted or membrane staining; antibody epitope dependence is unspecified in this evidence. |
| Can IF/ICC help assess localisation? | HPA reports supported cytosolic ICC-IF localisation and lists Hep-G2 and U2OS images, with the same multi-gene-target caution (HPA: subcellular; antibody HPA053817 ICC Supported). Use that finding as a localisation comparison; IF/ICC has its own guide, so this IHC section supplies no IF protocol. |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in liver hepatocytes. | This conflicts with a High reference population (HPA: liver hepatocytes); the cause cannot be inferred from the pattern alone. | Check a known-positive control section, primary-antibody application and detection reagents before interpreting the specimen (general IHC practice). |
| Colour is predominantly nuclear or membrane-like. | The compartment differs from the cytoplasmic expectation (UniProt P08263; HPA: tissue IHC). | Review morphology, counterstain and controls; record the pattern as unexpected until independently supported (general IHC practice). |
| Broad staining appears in adipocytes or marrow hematopoietic cells. | Both are reported Not detected (HPA: tissue IHC); nonspecific binding or endogenous detection activity is possible (general IHC practice). | Compare primary-omission and detection controls, then assess whether signal tracks the expected cell types (general IHC practice). |
| Diffuse background obscures cellular boundaries. | The expected distinct cytoplasmic distribution cannot be assessed (HPA: tissue IHC); excess background can arise during IHC processing (general IHC practice). | Review blocking, washing and detection controls, then score only interpretable cellular staining (general IHC practice). |
| Different antibodies give conflicting tissue patterns. | HPA reports medium RNA–staining consistency and cautions that antibodies may target multiple genes (HPA: tissue IHC). | Compare compartment and cell type across the same control tissues; report the disagreement rather than merging scores (general IHC practice). |
| A low-staining population appears negative. | Small-intestinal enterocytes, epididymal glandular cells and breast glandular cells are reported Low (HPA: tissue IHC). | Judge run performance using a High population such as hepatocytes, then interpret the low-staining population cautiously (HPA: tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing GSTA1 staining
A01462-1 · IHCIHC analysis of GSTA1/A2/A3/A4/A5 using anti-GSTA1/A2/A3/A4/A5 antibody (A01462-1). GSTA1/A2/A3/A4/A5 was detected in paraffin-embedded sect
A01462-1 · IHCIHC analysis of GSTA1/A2/A3/A4/A5 using anti-GSTA1/A2/A3/A4/A5 antibody (A01462-1). GSTA1/A2/A3/A4/A5 was detected in paraffin-embedded sect
PB9627 · IFIF analysis of GSTA1/A2/A3/A4/A5 using anti-GSTA1/A2/A3/A4/A5 antibody (PB9627) GSTA1/A2/A3/A4/A5 was detected in paraffin-embedded section
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000243955-GSTA1/tissue/cerebral+cortex#imid_14673552
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000243955-GSTA1/tissue/colon#imid_14669830
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000243955-GSTA1/tissue/liver#imid_14669815
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000243955-GSTA1/tissue/kidney#imid_14669816
HPA · ICC-IF Hep-G2Human Protein Atlas immunofluorescence, Hep-G2, antibody HPA053817; green = GSTA1, blue = nucleus, red = microtubules.
HPA · ICC-IF Hep-G2Human Protein Atlas immunofluorescence, Hep-G2, antibody HPA053817; green = GSTA1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for GSTA1 IHC & IF
🧪Run liver first: hepatocytes should stain (HPA: High in hepatocytes). Use adipose tissue as the negative tissue, with adipocytes at background (HPA: Not detected in adipocytes); on the liver slide, compare hepatocytes with nearby nonhepatocyte cells and assess their background staining rather than assuming they are GSTA1-negative.
Positive control tissue: Adrenal gland (Glandular cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show GSTA1 in Hep-G2, U2OS, with annotated localisation: Cytosol (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and a concentration-matched rabbit IgG isotype control (selected-SKU caption: rabbit primary antibody); use a GSTA1 knockout sample as a biological specificity control where available. Block endogenous peroxidase for chromogenic IHC and assess endogenous biotin background if using the caption’s biotin-based detection in liver (selected-SKU caption: biotinylated secondary and SABC–DAB).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the exact selected-SKU paraffin-section caption does not state a fixative (selected-SKU caption: fixative not stated). The caption uses citrate retrieval at pH 6 for 20 minutes, but does not establish that retrieval is required (selected-SKU caption); the supplied evidence also does not establish whether frozen sections or IF are easier. Assess liver background from endogenous peroxidase or biotin in chromogenic IHC and autofluorescence in IF; the selected-SKU caption labels its antibody GSTA1/A2/A3/A4/A5, so staining with it alone cannot establish GSTA1 specificity (selected-SKU caption).
HPA tissue IHC evidence for GSTA1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — Medium consistency between antibody staining and RNA expression data. Caution, targets protein from more than one gene.). 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Duodenum | Endocrine cells | High | Protein (IHC) | HPA → |
| Gallbladder | Glandular cells | High | Protein (IHC) | HPA → |
| Kidney | Cells in tubules | High | Protein (IHC) | HPA → |
| Liver | Hepatocytes | High | 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 → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced GSTA1 IHC Tips
Troubleshoot paraffin-section GSTA1 staining by checking retrieval, cytoplasmic localisation, antibody specificity and cell-level controls before comparing samples.
How should I retrieve GSTA1 in paraffin sections when staining is weak?
Use heat-mediated citrate buffer at pH 6 for paraffin-section GSTA1 IHC (datasheet A01462-1). The selected antibody's tissue-IHC caption reports 20 minutes of retrieval in that buffer, followed by overnight primary incubation at 4°C (caption A01462-1). If staining remains weak, compare a slightly longer citrate retrieval with the documented condition on adjacent sections, keeping detection and exposure identical (standard IHC practice). Include a section with expected hepatocyte staining and a no-primary control to distinguish retrieval failure from nonspecific signal (HPA: High in hepatocytes; standard IHC practice). Avoid interpreting stronger staining alone as improved GSTA1 specificity because this antibody also targets other alpha GST proteins (caption A01462-1).
Could fixation explain weak or uneven GSTA1 staining?
Target-specific fixation sensitivity is unknown because the selected tissue-IHC caption does not report a fixative (caption A01462-1). Record the fixative, time before fixation and fixation duration for each specimen, then compare sections processed together with the same retrieval and detection settings (standard IHC practice). If fixation differs between samples, test adjacent sections under the documented citrate pH 6, 20-minute retrieval condition before comparing staining intensity (caption A01462-1; standard IHC practice). Use hepatocyte-rich liver as an expected-positive comparator where available, and assess tissue preservation alongside staining (HPA: High in hepatocytes; standard IHC practice). Do not assign a weak result specifically to GSTA1 fixation sensitivity without a controlled comparison.
Where should convincing GSTA1 staining appear in a paraffin section?
Look primarily for cytoplasmic staining: UniProt places GSTA1 in the cytoplasm, and HPA reports supported cytosolic localisation (UniProt P08263; HPA subcellular). HPA describes high staining in liver hepatocytes and kidney tubular cells, providing cell-level comparators for section review (HPA tissue IHC). Score cytoplasm separately from nuclei and luminal deposits, using the same counterstain and magnification across samples (standard IHC practice). The protein has no transmembrane segment or signal peptide, so a purely crisp membrane pattern warrants a specificity check (UniProt P08263 topology and processing). Compare that pattern with a no-primary control and adjacent expected-positive tissue before calling it GSTA1 (standard IHC practice).
Can this antibody distinguish GSTA1 from related alpha GST proteins?
Treat a positive chromogenic result as alpha GST staining until specificity is established: the selected antibody is described as recognizing GSTA1/A2/A3/A4/A5 (caption A01462-1). HPA likewise cautions that its tissue staining targets proteins from more than one gene (HPA tissue IHC). UniProt lists no GSTA1 isoforms but describes GSTA1 homodimers or heterodimers with GSTA2; neither fact establishes this antibody's epitope (UniProt P08263). N-terminal processing and modifications at residues 1, 2 and 4 are annotated, so avoid assuming an N-terminal epitope without mapping data (UniProt P08263). For GSTA1-specific conclusions, compare staining with an independently validated discriminator or an appropriate genetic control (standard IHC practice).
How can I check the IHC pattern using multiplex immunofluorescence?
Use IF as a separate validation experiment; the selected caption documents paraffin-section chromogenic IHC, while HPA reports ICC/IF images in Hep-G2 and U2OS without establishing this SKU's IF conditions (caption A01462-1; HPA subcellular). Pair GSTA1 with a validated marker for the expected cell type, such as hepatocytes in liver, and inspect overlap at single-cell resolution (HPA: High in hepatocytes; standard IF practice). Choose a spectrally separated, preferably far-red fluorophore after measuring tissue autofluorescence in an unstained section (standard IF practice). Because GSTA1 is cytosolic and lacks a transmembrane segment, use mild permeabilisation appropriate for a cytosolic epitope and include a no-primary control (UniProt P08263; standard IF practice).
How do I reduce diffuse brown background without losing cytoplasmic signal?
Run a no-primary control through the full detection sequence to locate background from tissue, secondary antibody or chromogen (standard IHC practice). The documented method uses 10% goat-serum block, biotinylated anti-rabbit secondary, streptavidin-biotin detection and DAB; check each of those stages against the control (caption A01462-1). Apply a peroxidase block before DAB development and, with biotin-based detection, assess endogenous biotin interference where relevant (standard IHC practice). If background persists, titrate primary antibody around the documented 1 μg/ml while holding retrieval and development time constant (caption A01462-1; standard IHC practice). Preserve cytoplasmic staining in expected-positive hepatocytes as the practical sensitivity check (HPA tissue IHC).
How should I quantify GSTA1 IHC across samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the scored cell population and compartment before analysis; HPA reports high hepatocyte and kidney tubular-cell staining, while UniProt places GSTA1 in the cytoplasm (HPA tissue IHC; UniProt P08263). Report the percentage of positive target cells and a cytoplasmic H-score, using intensity grades 0–3 with the same thresholds across sections (standard IHC practice). Normalise counts to evaluable target cells or a defined tissue area in mm², and exclude folds, necrosis and section edges consistently (standard IHC practice). Process comparator sections together and keep retrieval, DAB development and imaging settings fixed (standard IHC practice). Label results as antibody-defined alpha GST staining unless GSTA1 specificity has been established independently (caption A01462-1).
When is a brown signal likely artefact rather than GSTA1?
A credible result has cellular cytoplasmic staining in an expected population, such as hepatocytes or kidney tubular cells, rather than only nuclear, luminal or edge staining (UniProt P08263; HPA tissue IHC; standard IHC practice). Review unexpected cell types against matched no-primary controls and tissue morphology before assigning positivity (standard IHC practice). Edge-only staining, necrotic debris and residual endogenous peroxidase signal can mimic DAB positivity, so inspect those regions separately and verify the peroxidase block (standard IHC practice). HPA reports no detection in adipocytes and several other listed populations, but its assay has multi-gene targeting caution (HPA tissue IHC). The selected antibody also recognizes GSTA1/A2/A3/A4/A5, so staining alone cannot establish GSTA1-specific expression (caption A01462-1).
Boster reagents
Best GSTA1 / Glutathione S-transferase A1 IHC Antibodies
Anti-GSTA1 family antibodies have paraffin-section IHC images from human lung and liver cancer tissue and IF images from mouse and rat liver (A01462-1 and PB9627 image captions).
Real IHC data
Anti-GSTA1/A2/A3/A4/A5 Antibody ®
Cat # A01462-1
Real IF data
Anti-GSTA1/GSTA2/GSTA3/GSTA4/GSTA5 Antibody ®
Cat # PB9627
A01462-1 will render with an IHC image from paraffin-embedded human lung cancer tissue; its catalog also lists human, mouse and rat reactivity (A01462-1 image caption and catalog). PB9627 will render with an IF image from paraffin-embedded mouse liver; its catalog also lists IF images from rat liver and IHC as an application (PB9627 image captions and catalog).
Which to pick: For tissue IHC, choose A01462-1 when a human paraffin-section example matters: its polyclonal antibody has human lung and liver cancer IHC images, but the captions do not report the fixative (A01462-1 catalog and image captions). For tissue IF, PB9627 has mouse and rat paraffin-section images; for ICC, A01462-3 lists ICC and IF but has no example image in the payload (PB9627 image captions; A01462-3 catalog). For work across human, mouse and rat, A01462-1 lists all three as reactive, while its pictured IHC evidence is human tissue (A01462-1 catalog and image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P08263 (GSTA1_HUMAN, Glutathione S-transferase A1).
- Human Protein Atlas. GSTA1 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. GSTA1 subcellular location (ICC-IF): Localized to the cytosol. Caution: Based on antibodies targeting proteins from multiple genes..
- Human Protein Atlas. GSTA1 antibody validation summary (3 antibodies).
- Oviductal Transcriptome Is Modified after Insemination during Spontaneous Ovulation in the Sow. PloS one 2015 — PMC4476686.
- Integrated analysis reveals GSTA1 as a prognostic biomarker in stage I lung adenocarcinoma. BMC cancer 2026 — PMC12997922.
- WGCNA-based identification of potential targets and pathways in response to treatment in locally advanced breast cancer patients. Open medicine (Warsaw, Poland) 2023 — PMC9990777.
- Glutathione S-transferase A1 suppresses tumor progression and indicates better prognosis of human primary hepatocellular carcinoma. Journal of Cancer 2020 — PMC6930411.
- PubMed PMID:3800996 — UniProt-cited evidence.
- PubMed PMID:3036131 — UniProt-cited evidence.
- PubMed PMID:3678589 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for GSTA1 (Glutathione S-transferase A1). Expected localisation Cytoplasmic staining in several tissues (HPA tissue IHC). Antigen retrieval: Citrate pH 6 HIER, heat-mediated (datasheet A01462-1). Validated IHC antibody: A01462-1 at 1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human lung cancer tissues; fixative not specified (datasheet A01462-1); 2. Fixation: Image fixative and duration unreported (datasheet A01462-1); 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: Citrate pH 6 , 20 min (datasheet A01462-1); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01462-1); 8. Primary antibody: Rabbit anti-GSTA1, 1μg/ml (datasheet A01462-1); 9. Primary incubation: Overnight at 4 °C (datasheet A01462-1). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: The antibody also recognizes GSTA2–5 (datasheet A01462-1); Isoform / epitope: No annotated isoforms; N-terminal processing removes residue 1 (UniProt); Regulation: Tissue-specific expression in liver (UniProt). Evidence: UniProt P08263, HPA tissue IHC · Supported, HPA ICC-IF · cytosol. Caution: Based on antibodies targeting proteins from…, Datasheet A01462-1, PMC4476686, PMC12997922. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/GSTA1/immunohistochemistry-ihc-guide.