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PIK3CG / Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit gamma isoform · IHC design guide
Design Immunohistochemistry for PIK3CG
Plan PIK3CG chromogenic IHC around cytoplasmic and membranous tissue staining (HPA tissue IHC). This guide covers the catalog antibody’s 2–5 μg/mL IHC range (datasheet A01517-2) and the presumed off-target staining caveat (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PIK3CG Immunohistochemistry Experimental Design Guide
Expected localisation, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before staining
| Expected localisation | Cytoplasmic and membranous tissue staining (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic and membranous staining, including lymphoid tissue (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A01517-2) | |
| 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 samples (standard IHC practice; not target-specific) | |
| Caveat | Presumed off-target binding can confound staining (HPA tissue IHC) | |
| Regulation | Expression regulation is not established by this record (UniProt) | |
| Isoform / epitope | One full-length chain; no alternative isoforms listed (UniProt) |
Section 1
Recommended PIK3CG IHC & IF Protocols
The catalog antibody has an IHC-P protocol (datasheet: A01517-2). One published PIK3CG IHC method provides additional incubation and detection details (PMC8805872).
| Sample | Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet A01517-2) |
| Fixation | Image fixative and duration unreported (datasheet A01517-2); 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 A01517-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01517-2) |
| Primary antibody | Rabbit anti-PIK3CG, 2-5μg/ml (datasheet A01517-2) |
| Primary incubation | Overnight at 4 °C (datasheet A01517-2) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A01517-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | PIK3CG-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic and membranous expression in several different tissue types, including lymphoid tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 for the catalog antibody (datasheet: A01517-2); the published method does not report retrieval (PMC8805872).
Section 2
What Is the Expected PIK3CG Staining Pattern?
PIK3CG is a cytoplasmic and cell membrane protein with no transmembrane segment (UniProt P48736 topology). In paraffin section IHC, expect cytoplasmic and membranous staining in several tissue types, including lymphoid tissue; hematopoietic cells in bone marrow show medium staining (HPA tissue IHC). HPA rates the tissue profile Enhanced, while noting medium consistency with RNA data and presumed off target binding that was disregarded (HPA tissue IHC).
| Cytoplasmic staining with a membranous component in hematopoietic cells; bone marrow signal is around medium (HPA tissue IHC). | This fits the reported tissue pattern and PIK3CG localization (HPA tissue IHC; UniProt P48736 subcellular location). Judge staining in identified cells, since the HPA profile describes several tissue types and does not imply uniform staining throughout a section (HPA tissue IHC). |
| Glandular cells in adrenal gland, appendix, breast, duodenum, endometrium, fallopian tube or gallbladder show medium staining (HPA tissue IHC). | These are additional reported positive cell and tissue combinations (HPA tissue IHC). Score the glandular cells themselves; staining of adjacent cells does not establish that those cells share the reported pattern. Interpret both location and intensity before calling a section positive (general IHC practice). |
| Signal is predominantly nuclear, with little cytoplasmic or membranous staining. | That compartment does not match the reported PIK3CG locations (UniProt P48736 subcellular location; HPA tissue IHC). Recheck morphology, counterstain and antibody dependent staining before interpreting nuclear signal as target specific (general IHC practice). |
| Strong staining appears in adipocytes, cardiomyocytes or lung alveolar cells, despite their reported absence of staining (HPA tissue IHC). | Consider cross reactivity or endogenous detection activity and inspect cell identity and compartment (general IHC practice). HPA reports these specific cell types as not detected, but its tissue profile also notes presumed off target binding; an unexpected positive needs independent validation (HPA tissue IHC). |
| Broad, hazy color obscures cell boundaries, or a reported positive section has no discernible signal. | Diffuse background prevents a reliable compartment call (general IHC practice). For an absent signal, first verify that the section contains the reported positive cells, such as bone marrow hematopoietic cells, before changing the biological interpretation (HPA tissue IHC; general IHC practice). |
💡Expected PIK3CG appearanceCall a positive when identifiable cells show cytoplasmic and membranous staining, with medium signal in the reported bone marrow hematopoietic or listed glandular cell examples; isolated nuclear staining or strong signal in HPA not detected cell types needs scrutiny (HPA tissue IHC; UniProt P48736 subcellular location).
| Compartment and topology (UniProt P48736 topology; HPA tissue IHC) | PIK3CG has no transmembrane segment, yet both cytoplasmic and membranous locations are reported (UniProt P48736 topology and subcellular location; HPA tissue IHC). A membrane associated appearance is therefore plausible; a sharp membrane outline in every cell is not required by these sources. |
| Cell and tissue context (HPA tissue IHC) | HPA reports medium staining in bone marrow hematopoietic cells and several specified glandular cell populations, but not detected staining in selected other cell populations (HPA tissue IHC). Compare like cell types within a section; a whole tissue label alone is too coarse for scoring. |
| Evidence strength (HPA tissue IHC; HPA antibody validation) | HPA labels the tissue profile Enhanced and antibody HPA069976 IHC Enhanced, while describing medium agreement with RNA data and disregarded presumed off target binding (HPA tissue IHC; HPA antibody validation). Treat a matching pattern as supportive evidence, with discrepant staining requiring its own check. |
| Cardiac and liver interpretation (UniProt P48736 tissue specificity; HPA tissue IHC) | UniProt lists heart and liver in tissue specificity, whereas HPA reports cardiomyocytes not detected and hepatocytes low by IHC (UniProt P48736 tissue specificity; HPA tissue IHC). These entries should not be converted into an expectation of strong staining in either cell type. |
| IF/ICC localization (HPA subcellular ICC-IF) | HPA ICC-IF reports a supported main plasma membrane location with additional supported cytosolic localization (HPA subcellular ICC-IF). This helps interpret compartment agreement, but an ICC-IF image does not establish an IHC paraffin section protocol or a tissue staining intensity. |
| Situation | Likely cause | Next action |
|---|---|---|
| A reported positive cell population is absent or very weak in the stained section. | The section may lack the relevant cells, or the IHC detection run may have failed; HPA reports medium bone marrow hematopoietic and specified glandular cell staining (HPA tissue IHC; general IHC practice). | Confirm the cell population on the counterstained section and run an appropriately matched positive control. Review the catalog antibody's IHC-P instructions for the validated assay conditions before adjusting retrieval or dilution (general IHC practice). |
| Staining is mainly nuclear or has no credible cytoplasmic or membranous component. | The location conflicts with the reported target pattern (UniProt P48736 subcellular location; HPA tissue IHC). Counterstain overlap or nonspecific detection can complicate the reading (general IHC practice). | Inspect the same cell boundaries and nuclei at higher magnification; compare with an appropriate control section and the antibody validation pattern. Do not score isolated nuclear color as a matching PIK3CG pattern (general IHC practice; HPA tissue IHC). |
| A tissue is called positive solely because some cells in it stain. | HPA observations are cell specific: for example, its bone marrow entry names hematopoietic cells and its adrenal entry names glandular cells (HPA tissue IHC). | Record tissue, identified cell type, compartment and intensity together. Compare the scored cell type with HPA's reported cell type, and assess unexpected neighboring cell staining separately (HPA tissue IHC; general IHC practice). |
| Color appears broadly across the section or persists where primary antibody was omitted. | Nonspecific background or endogenous activity in the chromogenic detection system may contribute (general IHC practice). HPA also notes presumed off target binding in its tissue profile (HPA tissue IHC). | Check a primary antibody omission control and the detection system's recommended blocking steps; inspect whether color follows tissue structures and survives control conditions before assigning target staining (general IHC practice). |
| Strong staining occurs in cells HPA calls not detected, including adipocytes or cardiomyocytes. | The result differs from those cell specific HPA IHC observations; off target binding is a possible explanation, but a single discrepant section does not establish its cause (HPA tissue IHC; general IHC practice). | Reconfirm cell identity and compare controls and compartment pattern. Seek independent antibody or orthogonal evidence before reporting a new PIK3CG positive population; note the HPA discrepancy in the interpretation (HPA tissue IHC; general IHC practice). |
| Can an IF/ICC result resolve an IHC localization question? | HPA ICC-IF supports plasma membrane and cytosolic localization, while HPA tissue IHC reports cytoplasmic and membranous staining (HPA subcellular ICC-IF; HPA tissue IHC). The preparations answer related compartment questions under different assay conditions. | Use ICC-IF as a localization cross check and evaluate paraffin section staining against the tissue IHC pattern and its cell specific controls. Keep IF/ICC assay setup in its separate guide (HPA subcellular ICC-IF; HPA tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing PIK3CG staining
A01517-2 · IHCIHC analysis of PI3K-gamma/PIK3CG using anti PI3K-gamma/PIK3CG antibody (A01517-2). PI3K-gamma/PIK3CG was detected in paraffin-embedded sect
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000105851-PIK3CG/tissue/cerebral+cortex#imid_20552843
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000105851-PIK3CG/tissue/colon#imid_20552753
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000105851-PIK3CG/tissue/liver#imid_20552770
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000105851-PIK3CG/tissue/kidney#imid_20552755
HPA · ICC-IF HELHuman Protein Atlas immunofluorescence, HEL, antibody HPA069976; green = PIK3CG, blue = nucleus, red = microtubules.
HPA · ICC-IF HELHuman Protein Atlas immunofluorescence, HEL, antibody HPA069976; green = PIK3CG, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PIK3CG IHC & IF
🧪Run adrenal gland first: glandular cells should stain (HPA: Medium in adrenal gland glandular cells). Use adipose tissue as the negative tissue, where adipocytes should show background staining (HPA: Not detected in adipocytes); within the adrenal section, use other cells as internal negative comparators only if they remain at background, since no negative adrenal cell type is specified (HPA: adrenal gland row).
Positive control tissue: Adrenal gland (Glandular cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PIK3CG in HEL, HUVEC/TERT2, with annotated localisation: Plasma membrane (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 validated PIK3CG knockout specimen as a biological negative. For chromogenic detection, quench endogenous peroxidase and check for endogenous biotin signal in the selected SABC/DAB workflow (selected-SKU caption: SABC and DAB).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected-SKU paraffin-section caption does not state the fixative (selected-SKU caption: fixative unreported). The reported IHC procedure uses heat retrieval in EDTA at pH 8.0, but the evidence does not establish whether retrieval is required for every specimen (selected-SKU caption: EDTA heat retrieval). The supplied evidence does not establish whether frozen sections or IF are easier; background from endogenous peroxidase or biotin should be checked in the chosen chromogenic workflow (selected-SKU caption: SABC/DAB).
HPA tissue IHC evidence for PIK3CG
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. Presumed off target binding observed and disregarded.). 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 | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Breast | Glandular cells | Medium | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Not detected | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced PIK3CG IHC Tips
Troubleshoot PIK3CG staining by checking retrieval, compartment, cell identity and controls before comparing signal across paraffin sections (UniProt P48736; HPA tissue IHC).
Which retrieval condition should I try first for weak PIK3CG staining?
Start with heat mediated retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A01517-2). The selected tissue image used this condition, followed by 2 µg/mL primary antibody overnight at 4°C (datasheet A01517-2). If staining remains weak, vary heating duration on matched sections while keeping antibody concentration and detection constant (standard IHC practice). Compare cytoplasmic and membranous signal in hematopoietic cells with background in adipocytes, which HPA reports as undetected (HPA tissue IHC). Record whether stronger retrieval improves cellular staining or merely increases diffuse DAB, and include a no primary control (standard IHC practice).
Could fixation explain variable PIK3CG staining between paraffin blocks?
Target specific fixation sensitivity is unknown because the selected paraffin section caption does not state a fixative (datasheet A01517-2). Do not attribute differences between blocks to a particular fixative without processing records and a controlled comparison (standard IHC practice). For comparable IHC results, document fixation type and duration, section thickness, retrieval, and time from sectioning to staining (standard IHC practice). Run affected blocks together using EDTA at pH 8.0 and the same detection sequence used for the selected image (datasheet A01517-2). Compare staining within the same identified cell population, since tissue composition can change the apparent PIK3CG signal (HPA tissue IHC; standard IHC practice).
Should I expect PIK3CG at the membrane or in the cytoplasm?
Score PIK3CG in the cytoplasm and along the cell membrane, consistent with tissue staining reported for several tissue types (HPA tissue IHC). Plasma membrane is the supported main location in cell imaging, with cytosol an additional supported location (HPA subcellular). PIK3CG has no transmembrane segment, so a membrane associated pattern need not resemble a membrane spanning receptor (UniProt P48736 topology). Assess membranous and cytoplasmic staining separately in intact cells, using adjacent unstained structures to judge DAB spread (standard IHC practice). Strong isolated nuclear staining should prompt review of controls and cell boundaries before assigning a PIK3CG score (UniProt P48736 subcellular; standard IHC practice).
How can I assess an unexpected PIK3CG staining pattern without epitope information?
The supplied record annotates 0 isoforms and a single chain spanning residues 1–1102 (UniProt P48736). It lists PI3K-ABD, PI3K-RBD, C2, helical and catalytic domains, but gives no epitope for the catalog antibody (UniProt P48736; datasheet A01517-2). Phosphorylation is annotated at residues 1024 and 1101; its effect on this antibody's staining is unreported (UniProt P48736; datasheet A01517-2). Check antibody epitope documentation before attributing a discrepant pattern to a domain or modification (standard IHC practice). Compare cellular localisation and staining in an independently characterized positive specimen, with a no primary control processed alongside it (standard IHC practice).
How should I check PIK3CG localisation by multiplex IF?
For IF, pair PIK3CG with a leukocyte marker such as CD45 when identifying hematopoietic cells in bone marrow (HPA tissue IHC; standard IF practice). Select a fluorophore channel with low tissue autofluorescence and inspect unstained tissue before interpreting faint signal (standard IF practice). PIK3CG is mainly plasma membrane associated with additional cytosolic localisation, and has no transmembrane segment (HPA subcellular; UniProt P48736 topology). If the antibody recognizes an intracellular epitope, optimize permeabilisation so antibody can reach it while preserving membrane boundaries (standard IF practice). Use single stain and no primary controls to check bleed through and background before judging colocalisation (standard IF practice).
What should I change when DAB obscures cellular PIK3CG staining?
The selected paraffin section image used 10% goat serum blocking, 2 µg/mL primary antibody overnight at 4°C, and biotin based DAB detection (datasheet A01517-2). Start by reviewing a no primary control and the distribution of deposits outside intact cells (standard IHC practice). If background persists, check peroxidase blocking, washing and DAB development time on matched sections (standard IHC practice). Biotin based detection also warrants an endogenous biotin control where tissue background is suspected (standard IHC practice; datasheet A01517-2). Preserve any discrete cytoplasmic or membranous staining while adjusting the workflow, since both compartments are supported for PIK3CG (HPA tissue IHC).
How should I quantify PIK3CG across sections with different cell mixtures? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring because PIK3CG can show cytoplasmic and membranous staining (HPA tissue IHC). Within that population, report percent positive cells and an H-score from intensity categories, or positive cell density per mm² for spatial comparisons (standard IHC practice). Normalize positive counts to the number of eligible cells, and density to analyzed viable tissue area (standard IHC practice). Record the number of sections and sampled fields, keeping thresholds and imaging settings consistent across cases (standard IHC practice). Separate hematopoietic from other cells where possible, since HPA reports medium staining in bone marrow hematopoietic cells (HPA tissue IHC).
How can I distinguish genuine PIK3CG signal from a staining artefact?
A plausible positive follows intact cell boundaries or cytoplasm, matching the reported PIK3CG distribution (HPA tissue IHC; HPA subcellular). Check cell identity before interpreting intensity: bone marrow hematopoietic cells show medium staining, whereas adipocytes are reported as undetected (HPA tissue IHC). Treat isolated nuclear deposits, section edge intensification and staining over necrosis as suspicious until controls resolve them (UniProt P48736 subcellular; standard IHC practice). Compare a no primary slide and peroxidase blocked tissue to identify detection background or endogenous enzyme activity (standard IHC practice). HPA notes presumed off target binding in its tissue assessment, so corroborate unexpected cell patterns independently (HPA tissue IHC).
Boster reagents
Best PIK3CG / Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit gamma isoform IHC Antibodies
A01517-2 has human paraffin-section IHC data (A01517-2 IHC caption). The catalog lists human, mouse and rat reactivity, with no IF/ICC validation (catalog applications/reactivity).
Real IHC data
Anti-PI3K-gamma/PIK3CG Antibody ®
Cat # A01517-2
A01517-2 is the only SKU and shows staining in a paraffin-embedded human breast cancer section (A01517-2 IHC caption). Its listed applications include IHC but exclude IF/ICC; its listed reactivity is human, mouse and rat (catalog applications/reactivity).
Which to pick: For human tissue IHC, choose A01517-2: this rabbit antibody has a paraffin-section image and a human IHC dilution of 2–5 μg/ml (catalog host/dilution; A01517-2 IHC caption). No SKU has IF/ICC validation in the supplied catalog (catalog applications; IF image alts). For mouse or rat work, A01517-2 lists reactivity, but the supplied IHC dilution and tissue image cover human samples only; the caption does not report the fixative (catalog reactivity/dilution; A01517-2 IHC caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P48736 (PK3CG_HUMAN, Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit gamma isoform).
- Human Protein Atlas. PIK3CG tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. PIK3CG subcellular location (ICC-IF): Mainly localized to the plasma membrane. In addition localized to the cytosol..
- Human Protein Atlas. PIK3CG antibody validation summary (1 antibodies).
- Revealing the Effects of the Herbal Pair of Euphorbia kansui and Glycyrrhiza on Hepatocellular Carcinoma Ascites with Integrating Network Target Analysis and Experimental Validation. International journal of biological sciences 2016 — PMC4852206.
- The potential therapeutic regimen for overcoming resistance to osimertinib due to rare mutations in NSCLC. iScience 2023 — PMC10320197.
- Inhibition of PI3K Isoform p110γ Increases Both Anti-Tumor and Immunosuppressive Responses to Aggressive Murine Head and Neck Squamous Cell Carcinoma with Low Immunogenicity. Cancers 2021 — PMC7956466.
- Repressing phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma by microRNA-142-3p restrains the progression of hepatocellular carcinoma. Bioengineered 2022 — PMC8805872.
- PubMed PMID:7624799 — UniProt-cited evidence.
- PubMed PMID:12853948 — UniProt-cited evidence.
- PubMed PMID:12690205 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PIK3CG (Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit gamma isoform). Expected localisation Cytoplasmic and membranous tissue staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A01517-2). Validated IHC antibody: A01517-2 at 2-5μg/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 breast cancer tissue; fixative not specified (datasheet A01517-2); 2. Fixation: Image fixative and duration unreported (datasheet A01517-2); 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 A01517-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01517-2); 8. Primary antibody: Rabbit anti-PIK3CG, 2-5μg/ml (datasheet A01517-2); 9. Primary incubation: Overnight at 4 °C (datasheet A01517-2). Watch for: Fixation: Keep fixation consistent across samples (standard IHC practice; not target-specific); Caveat: Presumed off-target binding can confound staining (HPA tissue IHC); Isoform / epitope: One full-length chain; no alternative isoforms listed (UniProt); Regulation: Expression regulation is not established by this record (UniProt). Evidence: UniProt P48736, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the plasma membrane. In addition localized to…, Datasheet A01517-2, PMC8805872. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PIK3CG/immunohistochemistry-ihc-guide.