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PIK3R1 / Phosphatidylinositol 3-kinase regulatory subunit alpha · IHC design guide
Design Immunohistochemistry for PIK3R1
PIK3R1 shows general cytoplasmic tissue staining, with high signal in lung macrophages and placental trophoblasts (HPA tissue IHC). For paraffin IHC, the catalog antibody A00318-1 has a listed working range of 2–5 μg/ml (datasheet A00318-1).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PIK3R1 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 | General cytoplasmic staining (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining in lung macrophages (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A00318-1) | |
| Positive control | Bone marrow+4 more · see all | |
| Negative control | None in HPA (detected in all 45 tissues); use no-primary + isotype controls |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections (standard IHC practice; not target-specific) | |
| Caveat | Macrophage-rich areas may skew tissue-level scoring (HPA tissue IHC) | |
| Regulation | Expression varies by cell type (HPA tissue IHC) | |
| Isoform / epitope | 5 isoforms; map the antibody epitope for isoform coverage (UniProt) |
Section 1
Recommended PIK3R1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A00318-1) is accompanied by one published human HCC paraffin-section workflow (PMC6264640).
| Sample | Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet A00318-1) |
| Fixation | Image fixative and duration unreported (datasheet A00318-1); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A00318-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A00318-1) |
| Primary antibody | Rabbit anti-PIK3R1, 2-5 μg/ml (datasheet A00318-1) |
| Primary incubation | Overnight at 4 °C (datasheet A00318-1) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A00318-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | PIK3R1-positive staining in hematopoietic cells of bone marrow (HPA tissue IHC: High). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval (datasheet A00318-1); the published HCC workflow specifies EDTA but gives no pH or heating conditions (PMC6264640).
Section 2
What Is the Expected PIK3R1 Staining Pattern?
PIK3R1 should appear mainly in the cytoplasm of stained cells (UniProt P27986: cytoplasm; HPA tissue IHC: general cytoplasmic expression). HPA reports high staining in several cell populations, including lung macrophages, heart cardiomyocytes and cerebral cortex neurons (HPA tissue IHC). Its tissue IHC status is Approved, with medium consistency between staining and RNA data (HPA tissue IHC). PIK3R1 has no transmembrane segment (UniProt P27986 topology).
| Clear cytoplasmic staining in lung macrophages or heart cardiomyocytes, with little staining in adjacent unstained structures (HPA tissue IHC: High in both cell populations). | This fits the reported compartment and provides a useful positive comparison (HPA tissue IHC: general cytoplasmic expression; UniProt P27986: cytoplasm). Judge intensity within the named cell population: HPA's High designation describes its observed staining, not a required score for every specimen or staining run. |
| Predominantly nuclear staining, with little cytoplasmic signal in a population expected to stain strongly (HPA tissue IHC: general cytoplasmic expression). | Treat this as a localisation mismatch and investigate staining or interpretation artefact before calling it PIK3R1. HPA reports cytosol in ICC-IF, and UniProt reports cytoplasm (HPA subcellular: approved cytosol; UniProt P27986). PIK3R1 can interact with XBP1 isoform 2, but that interaction alone does not establish a nuclear PIK3R1 staining pattern (UniProt P27986). |
| Strong staining appears mainly in cells expected to show low staining, such as liver cholangiocytes, while a known-positive population is weak (HPA tissue IHC: Low in cholangiocytes; High in lung macrophages). | Check cell identification, antibody specificity and endogenous chromogen-producing activity (general IHC practice). Low HPA staining is not an absolute negative control: HPA reports low tissue RNA specificity and lists no negative cell populations (HPA tissue IHC). A surprising cell pattern therefore needs controls before it is labelled cross-reactivity. |
| Chromogen spreads across cells and surrounding tissue, obscuring cell boundaries and the cytoplasmic pattern. | Interpretation is unreliable when signal cannot be assigned to cells (general IHC practice). Review the no-primary control for detection background, then assess blocking, antibody concentration, washing and chromogen development (general IHC practice). Do not use a uniformly coloured section as evidence that every cell expresses PIK3R1. |
| No convincing staining in a well-preserved positive comparison, such as lung macrophages or heart cardiomyocytes (HPA tissue IHC: High). | Consider an unsuccessful staining run before concluding that the test specimen lacks PIK3R1 (general IHC practice). Check the antibody's documented IHC-P conditions, detection reagents and retrieval trial (general IHC practice). HPA's medium staining-to-RNA consistency limits how confidently any one specimen predicts intensity (HPA tissue IHC). |
💡Expected PIK3R1 appearanceCall the result positive when identifiable expected cells show predominantly cytoplasmic staining, potentially strong in HPA High populations such as lung macrophages, while isolated strong nuclear staining or uniform tissue-wide colour warrants investigation (HPA tissue IHC: High in macrophages and general cytoplasmic expression; HPA subcellular: approved cytosol; general IHC practice).
| Cell population and comparator (HPA tissue IHC) | HPA reports High staining in bone marrow hematopoietic cells, cerebellar molecular-layer cells, cerebral cortex neurons, fallopian tube glandular cells, cardiomyocytes, lung macrophages, lymph-node germinal-center cells and placental trophoblastic cells. It reports Low staining in cholangiocytes, smooth muscle cells and fibroblasts. Match the cell type when comparing sections; the Low entries are poor absolute-negative controls because HPA lists no negative population (HPA tissue IHC). |
| Antibody validation (HPA antibodies; HPA tissue IHC) | HPA001216 and CAB004268 each have Approved IHC status; HPA001216 also has Approved ICC status (HPA antibodies). The tissue summary has Approved reliability with medium staining-to-RNA consistency (HPA tissue IHC). These labels support use as reference observations but do not prove that every antibody, epitope or specimen will reproduce the same intensity. Confirm the antibody used and compare appropriate controls (general IHC practice). |
| Isoforms and epitope coverage (UniProt P27986) | UniProt lists 5 isoforms; isoforms 2 and 4 are present in skeletal muscle at protein level, and isoform 2 is reported in brain (UniProt P27986). Without an antibody epitope or isoform-coverage record in this payload, do not assign tissue intensity to a particular isoform. Likewise, the listed phosphorylation sites establish modifications, not an effect on IHC retrieval or staining (UniProt P27986). |
| IF/ICC Q&A (HPA subcellular; HPA antibodies) | Q: What localisation should an IF/ICC image show? A: Expect cytosolic signal as the main pattern (HPA subcellular: approved cytosol). HPA lists ICC-IF images and marks HPA001216 Approved for ICC (HPA subcellular; HPA antibodies). This is localisation context for the separate IF/ICC guide, not an IF protocol or a prediction of fluorescence intensity in paraffin sections. |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected cells are unstained in both the test and positive-comparison sections (HPA tissue IHC: High in lung macrophages or cardiomyocytes). | A run-level failure is possible when a documented positive population also lacks signal (general IHC practice). | Check antibody identity and documented IHC-P conditions; verify detection and chromogen steps, then assess retrieval using the antibody's instructions (general IHC practice). No PIK3R1-specific fixation sensitivity is established by the supplied sources. |
| The test section is weak, but expected cells in the positive comparison stain (HPA tissue IHC: High populations). | Biological variation, sampling or staining differences remain possible; HPA reports medium staining-to-RNA consistency (HPA tissue IHC). | Confirm the cell population and section quality, then compare a second suitable specimen or staining run before scoring absence (general IHC practice). Do not infer an isoform or fixation effect from intensity alone. |
| Nuclei dominate the signal while expected cytoplasm is faint (HPA tissue IHC: general cytoplasmic expression). | The pattern conflicts with HPA's approved cytosolic ICC-IF localisation and UniProt's cytoplasm annotation (HPA subcellular; UniProt P27986). | Review the counterstain and no-primary control, then reassess antibody concentration and detection background (general IHC practice). Score PIK3R1 localisation only where cell boundaries and cytoplasm are clear. |
| Broad brown staining persists across tissue, including spaces without identifiable cells. | Nonspecific binding, endogenous detection activity or excessive chromogen development can obscure localisation (general chromogenic IHC practice). | Compare a no-primary control; check blocking appropriate to the detection system, washing and development time (general IHC practice). Reassess the cell-specific pattern only after background is controlled. |
| Strong signal appears in an HPA Low population and little appears in an HPA High comparator (HPA tissue IHC). | Cell misidentification, cross-reactivity or endogenous detection activity may explain the mismatch (general IHC practice). HPA Low does not mean absent (HPA tissue IHC). | Confirm morphology and comparator identity; examine no-primary staining and, if available, an independently validated antibody (general IHC practice). Report the discrepancy rather than treating the Low population as a proven negative. |
| Staining hugs cell edges, with no clear cytoplasmic component. | PIK3R1 can be recruited to the plasma membrane during signalling, but its reported overall localisation is cytoplasmic or cytosolic (UniProt P27986; HPA subcellular). | Inspect higher magnification and a cytoplasmic positive comparison; exclude edge artefact and background with appropriate controls (general IHC practice). Avoid scoring edge-only colour as a definitive membrane pattern. |
Experiment evidence
IHC & IF images showing PIK3R1 staining
A00318-1 · IHCIHC analysis of PI 3 Kinase p85 alpha/PIK3R1 using anti-PI 3 Kinase p85 alpha/PIK3R1 antibody (A00318-1). PI 3 Kinase p85 alpha/PIK3R1 was d
A00318-1 · IHCIHC analysis of PI 3 Kinase p85 alpha/PIK3R1 using anti-PI 3 Kinase p85 alpha/PIK3R1 antibody (A00318-1). PI 3 Kinase p85 alpha/PIK3R1 was d
A00318-1 · IFIF analysis of PI 3 Kinase p85 alpha/PIK3R1 using anti-PI 3 Kinase p85 alpha/PIK3R1 antibody (A00318-1). PI 3 Kinase p85 alpha/PIK3R1 was de
M00318-3 · IHCMouse testis was stained with Anti-PI3-Kinase p85 α rabbit Antibody
M00318-3 · IHCHuman placenta was stained with Anti-PI3-Kinase p85 α rabbit Antibody
A00318Y463 · IHCImmunohistochemistry (IHC) analyzes of PI3K p85 α/γ (Y463) pAb in paraffin-embedded human breast carcinoma tissue at 1:100.
A00318Y467 · IHCImmunohistochemistry (IHC) analysis of PI3K p85α/p55γ pAb in paraffin-embedded human breast carcinoma tissue
A00318Y607 · IFImmunofluorescence analysis of BV2 cells using PI3K p85α/p55γ antibody at dilution of 1:50.
M00318-2 · IFImmunofluorescent analysis using the Antibody at 1:50 dilution.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000145675-PIK3R1/tissue/cerebral+cortex#imid_2168820
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000145675-PIK3R1/tissue/colon#imid_2168746
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000145675-PIK3R1/tissue/liver#imid_2168755
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000145675-PIK3R1/tissue/kidney#imid_2168764
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA001216; green = PIK3R1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA001216; green = PIK3R1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PIK3R1 IHC & IF
🧪Run bone marrow first: hematopoietic cells should show PIK3R1 staining (HPA: High in hematopoietic cells). HPA detects PIK3R1 in all 45 scored tissues, so use no-primary and isotype controls for the negative; any unstained cells on the positive slide should lack cytoplasmic signal above background, but the supplied HPA rows do not establish a target-negative internal cell population (HPA: no negative rows; UniProt P27986: cytoplasm).
Positive control tissue: Bone marrow (Hematopoietic cells, HPA High)
Negative control tissue: None in HPA: PIK3R1 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PIK3R1 in A-431, U-251MG, U2OS, ASC52telo, RPTEC/TERT1, hTERT-RPE1 (serum starved), with annotated localisation: Cytosol (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide, a host- and clonality-matched isotype control (rabbit IgG for the captioned primary), and PIK3R1-knockout material if available as a biological negative (caption: rabbit primary; standard IHC controls). In bone marrow, quench endogenous peroxidase and check for background from the biotin-based detection system before interpreting DAB staining (caption: biotinylated secondary, SABC and DAB; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A00318-1 paraffin-section caption does not state its fixative (caption: fixative unreported). The caption uses heat retrieval in EDTA at pH 8.0, but does not establish that this retrieval is required for every specimen (caption: EDTA retrieval). Whether frozen sections or IF are easier is unreported; HPA shows cytosolic ICC-IF localization in listed cell lines, while the supplied tissue procedure is paraffin-section IHC (HPA: Cytosol approved; caption: paraffin section).
HPA tissue IHC evidence for PIK3R1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium 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 → |
| Cerebellum | Cells in molecular layer | High | Protein (IHC) | HPA → |
| Cerebral cortex | Neuronal cells | High | Protein (IHC) | HPA → |
| Fallopian tube | Glandular cells | High | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: PIK3R1 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced PIK3R1 IHC Tips
Troubleshoot PIK3R1 staining in paraffin sections by checking retrieval, cell identity, cytoplasmic localisation and controls before interpreting signal intensity.
How should I troubleshoot weak PIK3R1 staining after antigen retrieval?
Begin with heat-mediated retrieval in EDTA at pH 8.0 for paraffin-section PIK3R1 staining (datasheet A00318-1). The catalog image used this retrieval before overnight incubation at 4°C with 2 μg/ml primary antibody, so compare those steps before changing the retrieval chemistry (datasheet A00318-1). Include a section from the same block processed without primary antibody, and judge improvement by cellular staining rather than a darker background (standard IHC practice). If staining remains weak, test an alternative retrieval buffer on adjacent sections as a fallback, while keeping detection and exposure to chromogen consistent (standard IHC practice). Score the cytoplasm of identifiable cells because general cytoplasmic expression is expected (HPA: tissue IHC).
Could fixation explain weak or uneven PIK3R1 staining?
The catalog tissue caption identifies a paraffin section but does not report its fixative, so target-specific fixation sensitivity is unknown (datasheet A00318-1). Do not infer an optimal fixative or fixation duration from the reported staining pattern, the cytoplasmic location, or PIK3R1 modifications (datasheet A00318-1; HPA: tissue IHC; UniProt P27986). Compare sections with documented processing histories and keep retrieval, antibody concentration and detection identical while investigating uneven staining (standard IHC practice). Inspect morphology for poorly preserved areas and compare staining in intact cells away from section edges (standard IHC practice). Record the actual fixation conditions for each specimen before attributing intensity differences to PIK3R1 biology (standard IHC practice).
Should PIK3R1 appear on the cell surface or in nuclei?
Expect predominantly cytoplasmic chromogenic staining: UniProt places PIK3R1 in the cytoplasm, and HPA describes general cytoplasmic tissue expression (UniProt P27986; HPA: tissue IHC). PIK3R1 has no transmembrane segment, although its adaptor role can recruit the p110 complex toward activated membrane receptors (UniProt P27986). Therefore, membrane-adjacent cytoplasmic staining can be plausible, but a sharp membrane-only rim needs comparison with a no-primary control and cell morphology (UniProt P27986; standard IHC practice). Predominantly nuclear staining should prompt a check of counterstain, background and antibody specificity before biological interpretation (standard IHC practice). Compare the apparent compartment in several intact cells rather than relying on a single dark profile (standard IHC practice).
Can this stain distinguish PIK3R1 isoforms or modification states?
PIK3R1 has 5 listed isoforms, and isoforms 2 and 4 occur in skeletal muscle at protein level (UniProt P27986). The supplied catalog caption does not identify the antibody epitope, so its chromogenic signal cannot be assigned to a particular isoform from this evidence (datasheet A00318-1). PIK3R1 also carries reported phosphorylation sites, including Tyr-467 and Tyr-580, but this staining is not identified as modification-specific (UniProt P27986; datasheet A00318-1). Check epitope documentation before using variant-dependent conclusions, and use an independently validated isoform- or modification-specific assay if that distinction drives the experiment (standard IHC practice). Compare sections under identical retrieval and detection conditions when evaluating apparent biological differences (standard IHC practice).
How should I check PIK3R1 by IF alongside this IHC result?
Treat IF as a separate validation experiment because the supplied catalog procedure documents chromogenic staining of a paraffin section (datasheet A00318-1). Multiplex PIK3R1 with a validated macrophage marker when examining lung, where macrophages show high PIK3R1 staining, and include single-stain controls (HPA: high in lung macrophages; standard IF practice). Choose a fluorophore channel with low tissue autofluorescence and verify it using an unstained section before interpreting colocalisation (standard IF practice). PIK3R1 is cytosolic and has no transmembrane segment, so use an appropriately permeabilised preparation for an intracellular epitope, subject to that antibody’s IF validation (HPA: approved cytosol; UniProt P27986; standard IF practice). Keep IF signal patterns distinct from chromogenic IHC scores when reporting results (standard imaging practice).
What should I adjust when the PIK3R1 DAB background is high?
First compare the stained section with a no-primary control to separate primary-dependent signal from detection background (standard IHC practice). The catalog image used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, a biotinylated secondary, and DAB development (datasheet A00318-1). If background is widespread, review blocking, washing, primary concentration and development time one variable at a time; apply a peroxidase block as part of the chromogenic workflow (standard IHC practice). Evaluate possible background from the biotin-based detection system with an appropriate detection-only control (datasheet A00318-1; standard IHC practice). Preserve the expected cytoplasmic pattern when adjusting conditions, rather than treating every brown deposit as PIK3R1 (HPA: tissue IHC; standard IHC practice).
How should I quantify PIK3R1 staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and cytoplasmic compartment before scoring, because HPA reports general cytoplasmic expression across tissues (HPA: tissue IHC). For comparable regions, record the percentage of positive target cells and an H-score using a prespecified intensity scale, or count positive cells per mm² when density is the question (standard IHC practice). Normalise counts to viable tissue area and report cell-type-specific results against the total number of that cell type, rather than all nuclei (standard IHC practice). Keep retrieval, antibody concentration, DAB development and image thresholds consistent across batches, with a shared reference section where feasible (standard IHC practice). Report staining distribution alongside the summary score so focal background cannot dominate interpretation (standard IHC practice).
How can I distinguish true PIK3R1 signal from staining artefacts?
A credible result shows cellular cytoplasmic staining in a plausible population, consistent with UniProt localisation and HPA tissue patterns (UniProt P27986; HPA: tissue IHC). In lung, macrophages can stain strongly, so identify the stained cell type before assigning signal to neighbouring cells (HPA: high in lung macrophages). Treat isolated nuclear signal, section-edge accentuation, necrotic deposits and diffuse staining in the no-primary control as reasons to investigate artefact (UniProt P27986; standard IHC practice). Check endogenous peroxidase background with an appropriate control when interpreting DAB deposits (standard IHC practice). HPA rates its tissue staining Approved with medium consistency against RNA, so concordant localisation and controls strengthen an interpretation without establishing pathway activity (HPA: tissue IHC; standard IHC practice).
Boster reagents
Best PIK3R1 / Phosphatidylinositol 3-kinase regulatory subunit alpha IHC Antibodies
These anti-PIK3R1 reagents have IHC images from human and mouse tissues and IF images from Caco-2 and BV2 cells (catalog image captions); listed reactivity includes human, mouse and rat (catalog reactivity).
Real IHC data
Anti-PI 3 Kinase p85 alpha/PIK3R1 Antibody ®
Cat # A00318-1
Real IHC data
Anti-PI3-Kinase p85 α Rabbit Monoclonal Antibody
Cat # M00318-3
Real IHC data
Anti-PI3K p85 Alpha /p55 Gamma (Y463) PIK3R1 Antibody
Cat # A00318Y463
Real IHC data
Anti-PI3K p85 Alpha /p55 Gamma (Y467/199) PIK3R1 Antibody
Cat # A00318Y467
Real IF data
Anti-PI3K p85 Alpha /p55 Gamma (Tyr607) PIK3R1 Antibody
Cat # A00318Y607
Real IF data
Anti-PI3 Kinase p85 alpha Rabbit Monoclonal Antibody
Cat # M00318-2
A00318-1 shows IHC in paraffin sections of human lung cancer, lymphoma and testicular cancer and mouse brain (A00318-1 IHC captions); M00318-3 shows IHC in mouse testis and human placenta (M00318-3 IHC captions); A00318Y463 and A00318Y467 show IHC in paraffin sections of human breast carcinoma (respective IHC captions). A00318Y607 shows IF in BV2 cells (A00318Y607 IF caption), while M00318-2 has IF images with no sample identified (M00318-2 IF captions).
Which to pick: For paraffin-section IHC, choose A00318-1: its lung cancer image documents EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody overnight at 4°C; the fixative is unreported (A00318-1 IHC caption). For IF/ICC, choose A00318-1 for the documented Caco-2 cell image at 5 μg/ml (A00318-1 IF caption), or monoclonal M00318-2 for listed IF/ICC use, while its IF captions leave the sample unidentified (M00318-2 catalog applications, clone and IF captions). For cross-species tissue IHC, monoclonal M00318-3 has images from human placenta and mouse testis and lists rat reactivity; the captions do not report the fixative, and rat IHC is not shown (M00318-3 catalog clone, reactivity and IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P27986 (P85A_HUMAN, Phosphatidylinositol 3-kinase regulatory subunit alpha).
- Human Protein Atlas. PIK3R1 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. PIK3R1 subcellular location (ICC-IF): Localized to the cytosol..
- Human Protein Atlas. PIK3R1 antibody validation summary (2 antibodies).
- Correlation Between PIK3R1 Expression and Cell Growth in Human Breast Cancer Cell Line BT-474 and Clinical Outcomes. World journal of oncology 2025 — PMC11750754.
- Overexpression of PIK3R1 promotes hepatocellular carcinoma progression. Biological research 2018 — PMC6264640.
- PIK3R1 underexpression is an independent prognostic marker in breast cancer. BMC cancer 2013 — PMC4225603.
- The Potential Mechanisms of Cinobufotalin Treating Colon Adenocarcinoma by Network Pharmacology. Frontiers in pharmacology 2022 — PMC9262105.
- PubMed PMID:1849461 — UniProt-cited evidence.
- PubMed PMID:8628286 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PIK3R1 (Phosphatidylinositol 3-kinase regulatory subunit alpha). Expected localisation General cytoplasmic staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A00318-1). Validated IHC antibody: A00318-1 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Bone marrow (Hematopoietic cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human lung cancer tissue; fixative not specified (datasheet A00318-1); 2. Fixation: Image fixative and duration unreported (datasheet A00318-1); 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: EDTA pH 8.0 (datasheet A00318-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A00318-1); 8. Primary antibody: Rabbit anti-PIK3R1, 2-5 μg/ml (datasheet A00318-1); 9. Primary incubation: Overnight at 4 °C (datasheet A00318-1). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Macrophage-rich areas may skew tissue-level scoring (HPA tissue IHC); Isoform / epitope: 5 isoforms; map the antibody epitope for isoform coverage (UniProt); Regulation: Expression varies by cell type (HPA tissue IHC). Evidence: UniProt P27986, HPA tissue IHC · Approved, HPA ICC-IF · cytosol., Datasheet A00318-1, PMC6264640. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PIK3R1/immunohistochemistry-ihc-guide.