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PCK1 / Phosphoenolpyruvate carboxykinase, cytosolic [GTP] · IHC design guide
Design Immunohistochemistry for PCK1
Plan PCK1 paraffin-section IHC using cytoplasmic staining in kidney tubular cells as a positive reference (HPA tissue IHC). This guide covers fixation, detection and interpretation, including the low consistency between antibody staining and RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PCK1 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 tissue staining (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic kidney tubules and GI glandular cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A02022-3) | |
| Positive control | Kidney+4 more · see all | |
| Negative control | Adrenal gland+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep paraffin-section fixation consistent (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A02022-3) | |
| Caveat | Antibody staining has low consistency with RNA expression (HPA tissue IHC) | |
| Regulation | Up-regulated in memory CD8+ T cells (UniProt; by similarity) | |
| Isoform / epitope | 2 isoforms; verify antibody epitope coverage (UniProt) |
Section 1
Recommended PCK1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A02022-3) is paired with published PCK1 IHC workflows for xenograft, kidney, and liver sections (PMC11053060; PMC12128133; PMC6304441).
| Sample | Paraffin-embedded mouse kidney tissue; fixative not specified (datasheet A02022-3) |
| Fixation | Image fixative and duration unreported (datasheet A02022-3); 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 A02022-3); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A02022-3) |
| Primary antibody | Rabbit anti-PCK1, 0.5-1μg/ml (datasheet A02022-3) |
| Primary incubation | Overnight at 4 °C (datasheet A02022-3) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A02022-3) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | PCK1-positive staining in cells in tubules of kidney (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in several different tissue types, including kidney and gastrointestinal tract. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 for the catalog antibody (datasheet A02022-3). Citrate retrieval is reported for kidney sections (PMC12128133).
Section 2
What Is the Expected PCK1 Staining Pattern?
PCK1 is primarily cytosolic, with conditional translocation to the endoplasmic reticulum after Ser-90 phosphorylation; it has no transmembrane segment (UniProt P35558). In paraffin-section IHC, expect cytoplasmic staining in kidney tubular cells and some gastrointestinal glandular cells (HPA tissue IHC). HPA rates its tissue staining “Approved” but reports low consistency with RNA expression, so interpret unexpected patterns with controls (HPA tissue IHC).
| Strong cytoplasmic staining in kidney tubular cells. | This matches the clearest supplied positive reference: HPA reports high staining in kidney tubular cells (HPA tissue IHC). Compare the signal with adjacent cells and a matched negative control before scoring it as specific staining (standard IHC practice). |
| Moderate cytoplasmic staining in gastrointestinal glandular cells. | HPA reports medium staining in glandular cells of the appendix, colon, duodenum, rectum and small intestine (HPA tissue IHC). These are plausible positives, although staining intensity may differ from the high kidney tubular signal (HPA tissue IHC). |
| Predominantly nuclear staining or a sharp plasma-membrane outline. | These patterns do not match PCK1’s annotated cytosolic location or lack of a transmembrane segment (UniProt P35558). Treat them as suspect and check the negative control and antibody specificity before assigning them to PCK1 (standard IHC practice). |
| Strong staining in cells that HPA lists as undetected, such as bone-marrow hematopoietic cells. | HPA reports no detected staining in those cells (HPA tissue IHC). Cross-reactivity or endogenous chromogenic detection activity are possible explanations; a no-primary control can help distinguish detection background from primary-antibody staining (standard IHC practice). |
| No staining in kidney tubular cells, with otherwise intact tissue. | This conflicts with HPA’s high kidney tubular staining and warrants a technical check (HPA tissue IHC). Review the positive control, antibody incubation, detection reagents and retrieval conditions before interpreting an experimental sample as negative (standard IHC practice). |
💡Expected PCK1 appearanceCall a result positive when kidney tubular cells show strong cytoplasmic staining, with medium cytoplasmic staining also plausible in the listed gastrointestinal glandular cells; dominant nuclear or membrane-edge staining is suspect (HPA tissue IHC; UniProt P35558).
| Tissue and cell choice | Use kidney tubular cells as the strongest supplied positive reference; HPA rates them high (HPA tissue IHC). Liver is RNA-enhanced, but the supplied liver IHC entry specifies low staining in cholangiocytes, so do not infer a strong liver-slide positive from RNA alone (HPA tissue IHC). |
| Antibody evidence | HPA lists HPA006277, HPA006507 and CAB017027 as IHC “Approved,” while reporting low consistency between tissue staining and RNA data (HPA antibodies; HPA tissue IHC). Approval supports using the observed pattern as a reference, with controls for unexpected staining; no “Enhanced” validation is supplied (HPA antibodies). |
| Compartment and modification | PCK1 lacks a transmembrane segment and is annotated mainly in the cytosol (UniProt P35558). Ser-90 phosphorylation can promote endoplasmic-reticulum translocation, but these tissue IHC data do not establish when that state occurs or how to identify it on a slide (UniProt P35558; HPA tissue IHC). |
| Isoforms and antibody recognition | UniProt lists two PCK1 isoforms and several modified residues (UniProt P35558). The supplied records give no epitope map or isoform-specific IHC result, so staining cannot distinguish isoforms or modification states from these data alone (UniProt P35558; HPA antibodies). |
| IF/ICC: what pattern is supported? | A cytosolic signal is consistent with UniProt localisation, but HPA supplies no main ICC-IF location or cell-line images for PCK1 (UniProt P35558; HPA subcellular). This IHC tissue pattern therefore does not establish an IF/ICC cell-line reference pattern (HPA tissue IHC; HPA subcellular). |
| Situation | Likely cause | Next action |
|---|---|---|
| Kidney tubules are negative or unexpectedly faint. | The result conflicts with the high kidney tubular signal in the supplied reference; the cause is unresolved by the record (HPA tissue IHC). | Check the positive control, section integrity, antibody incubation and detection. Review retrieval against the antibody’s IHC instructions without assuming PCK1-specific retrieval sensitivity (standard IHC practice). |
| Staining is concentrated in nuclei or along cell borders. | The dominant pattern conflicts with cytosolic localisation and the absence of a transmembrane segment (UniProt P35558). | Inspect a matched no-primary control, verify antibody identity and compare a kidney positive control before scoring the pattern as PCK1 (standard IHC practice; HPA tissue IHC). |
| Brown signal appears broadly in cells listed as undetected. | Cross-reactivity or endogenous chromogenic activity may explain a signal that disagrees with the HPA cell-level observations (HPA tissue IHC; standard IHC practice). | Run a no-primary control and appropriate endogenous-enzyme blocking control; compare the suspect cells with kidney tubules on the same run (standard IHC practice; HPA tissue IHC). |
| A diffuse haze obscures cell boundaries. | Background from detection or incomplete blocking or washing may make cytoplasmic localisation difficult to judge (standard IHC practice). | Inspect the no-primary control, check blocking and washing, and assess whether reducing antibody concentration improves contrast while retaining the kidney positive signal (standard IHC practice; HPA tissue IHC). |
| A liver section is weak despite the RNA-enhanced label. | The supplied liver IHC observation is low staining in cholangiocytes; RNA enrichment does not specify strong protein staining in that sampled cell type (HPA tissue IHC). | Use kidney tubular cells to check assay performance, then report the liver cell type and observed intensity separately from the RNA classification (HPA tissue IHC; standard IHC practice). |
| Positive cells stain unevenly across a section. | Uneven staining can arise from section handling or reagent coverage, while the HPA record does not establish a PCK1-specific fixation effect (standard IHC practice; HPA tissue IHC). | Compare tissue morphology and control staining across the section; repeat with consistent processing if the unevenness tracks an edge or reagent-coverage pattern (standard IHC practice). |
Experiment evidence
IHC & IF images showing PCK1 staining
A02022-3 · IHCIHC analysis of PCK1/PEPC using anti-PCK1/PEPC antibody (A02022-3). PCK1/PEPC was detected in paraffin-embedded section of mouse kidney tiss
A02022-3 · IHCIHC analysis of PCK1/PEPC using anti-PCK1/PEPC antibody (A02022-3). PCK1/PEPC was detected in paraffin-embedded section of rat kidney tissue
A02022-3 · IFIF analysis of PCK1/PEPC using anti-PCK1/PEPC antibody (A02022-3). PCK1/PEPC was detected in immunocytochemical section of Hela cells. Enzym
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000124253-PCK1/tissue/cerebral+cortex#imid_2081640
HPA · DuodenumHuman Protein Atlas IHC, Duodenum. Source: https://www.proteinatlas.org/ENSG00000124253-PCK1/tissue/duodenum#imid_2081581
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000124253-PCK1/tissue/colon#imid_2081566
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000124253-PCK1/tissue/liver#imid_2081575
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PCK1 IHC & IF
🧪Run kidney first: tubular cells should show strong PCK1 staining (HPA: High in kidney tubular cells). Use adrenal glandular cells as a negative tissue (HPA: Not detected in adrenal glandular cells); on the kidney slide, cells outside the stained tubules should show only background signal as an internal comparator, without assuming every such cell is PCK1-negative (HPA: High in kidney tubular cells).
Positive control tissue: Kidney (Cells in tubules, HPA High)
Negative control tissue: Adrenal gland (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for PCK1; derive a cell-line control from the positive tissue's cell type (Cells in tubules) and confirm it by RNA or western blot first.
Technical controls: Include no-primary (secondary-only), matched nonimmune rabbit IgG isotype, and PCK1-knockout tissue or a validated peptide-block control (selected-SKU IHC caption: rabbit primary antibody). In kidney sections, quench endogenous peroxidase and assess endogenous biotin before using the caption’s biotin–SABC/DAB detection (selected-SKU IHC caption).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A02022-3 paraffin-section caption does not state the fixative (selected-SKU IHC caption). The reported workflow uses heat-mediated EDTA retrieval at pH 8.0; whether retrieval is essential is unreported (selected-SKU IHC caption). The supplied evidence does not establish whether frozen sections or IF are easier; kidney’s potential endogenous biotin is relevant to the caption’s biotin-based detection (selected-SKU IHC caption; HPA subcellular: no ICC-IF images).
HPA tissue IHC evidence for PCK1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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 |
|---|---|---|---|---|
| Kidney | Cells in tubules | High | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Colon | Glandular cells | Medium | Protein (IHC) | HPA → |
| Duodenum | Glandular cells | Medium | Protein (IHC) | HPA → |
| Rectum | Glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial 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 PCK1 IHC Tips
Troubleshoot PCK1 staining in paraffin sections by checking retrieval, compartment, cell type and controls before interpreting chromogenic signal.
Which retrieval condition should I start with for PCK1 in paraffin sections?
Start with heat-mediated retrieval in EDTA pH 8.0 for PCK1 paraffin-section IHC (datasheet A02022-3). The selected mouse kidney image used that condition before incubation with 1 μg/mL primary antibody overnight at 4°C (datasheet A02022-3). If staining is weak, check that heating, cooling and subsequent washes were consistent across sections before changing retrieval conditions (standard IHC practice). Compare any adjusted retrieval against the original EDTA pH 8.0 condition on adjacent sections, using kidney tubule cells as a reference for expected staining (datasheet A02022-3; HPA: High in kidney tubule cells; standard IHC practice).
Could fixation explain weak or uneven PCK1 staining?
Target-specific sensitivity of PCK1 to fixation is unknown from the supplied evidence; the selected paraffin-section caption does not state its fixative (datasheet A02022-3). Record the fixative, time in fixative and tissue processing history for each specimen before attributing a weak result to PCK1 biology (standard IHC practice). Compare sections processed together and use consistent section handling when assessing whether signal varies with preservation or staining conditions (standard IHC practice). Do not infer a suitable fixative from kidney staining, cytosolic localisation or PCK1 modification sites, because none establishes fixation performance (HPA: High in kidney tubule cells; UniProt P35558: cytosolic localisation and modified residues; datasheet A02022-3: fixative unstated).
How should I evaluate unexpected nuclear or membrane-like PCK1 staining?
Assess PCK1 primarily as a cytosolic signal, while allowing a possible endoplasmic-reticulum-associated pattern under the described Ser-90 phosphorylation state (UniProt P35558: subcellular localisation and Ser-90-dependent translocation). PCK1 has no annotated transmembrane segment, so a sharp plasma-membrane outline alone needs independent scrutiny (UniProt P35558: topology; standard IHC practice). Check whether the same pattern appears in kidney tubule cells, where tissue staining is reported as High, and compare it with a no-primary control (HPA: High in kidney tubule cells; standard IHC practice). Treat dominant nuclear staining cautiously and inspect counterstained morphology, section edges and detection background before assigning it to PCK1 (UniProt P35558: reported cytosolic and endoplasmic-reticulum localisation; standard IHC practice).
Can this IHC result distinguish PCK1 isoforms or phosphorylation states?
PCK1 has 2 annotated isoforms, but the supplied antibody caption does not identify its epitope or establish isoform-specific staining (UniProt P35558: isoforms 1 and 2; datasheet A02022-3). Its Ser-90 phosphorylation is associated with endoplasmic-reticulum translocation, yet a change in chromogenic distribution alone cannot identify that modification (UniProt P35558: Ser-90-dependent translocation; standard IHC practice). Check the antibody’s documented epitope and validation before making isoform or modification claims, and use an independently validated state-specific reagent if that distinction is essential (standard IHC practice). Score this assay as PCK1 immunoreactivity unless the relevant specificity has been demonstrated in tissue sections (standard IHC practice).
How would I investigate the PCK1 pattern with multiplex IF?
Use IF as a separate validation experiment alongside the chromogenic IHC result, since the supplied subcellular record lists no ICC/IF image set (HPA subcellular: no ICC/IF images; standard IF practice). Multiplex PCK1 with a validated marker for the expected kidney tubule cell population and examine whether both signals occupy the same cells (HPA: High in kidney tubule cells; standard IF practice). Choose fluorophores and controls after checking tissue autofluorescence in each channel, and keep acquisition settings consistent across comparisons (standard IF practice). For intracellular PCK1 epitopes, optimise permeabilisation to provide cytosolic access and, when testing an endoplasmic-reticulum-associated pattern, access to the relevant epitope without assuming a transmembrane domain (UniProt P35558: localisation and topology; standard IF practice).
What should I check when DAB appears throughout the section?
First compare the stained slide with a no-primary control and inspect whether the diffuse colour follows tissue structure or staining artefacts (standard IHC practice). The selected kidney protocol used 10% goat serum, a biotinylated goat anti-rabbit secondary, a streptavidin–biotin complex and DAB, so assess background at the blocking and detection steps as well as at the primary antibody step (datasheet A02022-3; standard IHC practice). Include an endogenous peroxidase block when using a peroxidase/DAB workflow, and check for detection-system background with appropriate controls (standard IHC practice). Compare cytosolic staining in kidney tubule cells against diffuse colour outside cells before calling a section PCK1-positive (HPA: High in kidney tubule cells; UniProt P35558: cytosolic localisation; standard IHC practice).
How should I score PCK1 across sections with different cell composition? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and region before scoring, then record cytoplasmic staining intensity and the percentage of positive cells for an H-score (UniProt P35558: cytosolic localisation; standard IHC practice). For kidney sections, report tubule-cell results separately from other compartments because High staining is reported specifically in cells in tubules (HPA: High in kidney tubule cells; standard IHC practice). Normalise cell-based scores to the number of evaluable cells in the defined population, or normalise positive-cell density to evaluable tissue area in mm² (standard IHC practice). Apply the same positivity threshold, counterstain assessment and exclusion rules for damaged or poorly preserved regions across every section (standard IHC practice).
When is a PCK1-positive section biologically convincing?
A convincing result shows predominantly cytoplasmic staining in an expected cell population, such as kidney tubule cells, with low signal in relevant staining controls (UniProt P35558: cytosolic localisation; HPA: High in kidney tubule cells; standard IHC practice). Evaluate a possible endoplasmic-reticulum-associated pattern cautiously: localisation alone does not establish Ser-90 phosphorylation (UniProt P35558: Ser-90-dependent translocation; standard IHC practice). Question isolated nuclear or plasma-membrane-like signal, staining concentrated at section edges or necrotic regions, and colour reproduced in the no-primary control (UniProt P35558: localisation and topology; standard IHC practice). Interpret weak or discordant staining conservatively because the tissue IHC record reports low consistency between antibody staining and RNA expression (HPA: Approved reliability with low staining–RNA consistency).
Boster reagents
Best PCK1 / Phosphoenolpyruvate carboxykinase, cytosolic [GTP] IHC Antibodies
PCK1 antibody data include paraffin-section IHC in mouse and rat kidney and IF in HeLa cells (A02022-3 image captions); human IHC is listed without a sample image (M02022-1 catalog).
Real IHC data
Anti-PCK1/PEPC Antibody ®
Cat # A02022-3
A02022-3 will render with mouse kidney paraffin-section IHC; its catalog also documents rat kidney IHC and HeLa cell IF (A02022-3 image captions). M02022-1 will render with human IHC listed as an application, but no sample image is supplied (M02022-1 catalog).
Which to pick: For kidney tissue IHC across mouse and rat, choose A02022-3; its captions document paraffin sections, while the fixative is unreported (A02022-3 IHC image captions). For IF/ICC, choose A02022-3, which lists both applications and shows HeLa cell IF (A02022-3 catalog and IF image caption). For human tissue IHC, M02022-1 is a rabbit monoclonal with human reactivity and IHC listed, but no tissue or processing example is supplied (M02022-1 catalog).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P35558 (PCKGC_HUMAN, Phosphoenolpyruvate carboxykinase, cytosolic [GTP]).
- Human Protein Atlas. PCK1 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. PCK1 subcellular location (ICC-IF): Highest expression in Hep-G2: 2.2 nTPM.
- Human Protein Atlas. PCK1 antibody validation summary (3 antibodies).
- Expression and functional significance of phosphoenolpyruvate carboxykinase 1 in uveal melanoma. Cell death discovery 2024 — PMC11053060.
- Protective effect of phosphoenolpyruvate carboxykinase 1 on inflammation and fibrotic progression of IgA nephropathy. Renal failure 2025 — PMC12128133.
- Pharmacologic Antagonization of Cannabinoid Receptor 1 Improves Cholestasis in Abcb4(-/-) Mice. Cellular and molecular gastroenterology and hepatology 2022 — PMC8873597.
- PCK1 Downregulation Promotes TXNRD1 Expression and Hepatoma Cell Growth via the Nrf2/Keap1 Pathway. Frontiers in oncology 2018 — PMC6304441.
- PubMed PMID:8490617 — UniProt-cited evidence.
- PubMed PMID:8325643 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PCK1 (Phosphoenolpyruvate carboxykinase, cytosolic [GTP]). Expected localisation Cytoplasmic tissue staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A02022-3). Validated IHC antibody: A02022-3 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Kidney (Cells in tubules); negative Adrenal gland. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded mouse kidney tissue; fixative not specified (datasheet A02022-3); 2. Fixation: Image fixative and duration unreported (datasheet A02022-3); 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 A02022-3); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A02022-3); 8. Primary antibody: Rabbit anti-PCK1, 0.5-1μg/ml (datasheet A02022-3); 9. Primary incubation: Overnight at 4 °C (datasheet A02022-3). Watch for: Fixation: Keep paraffin-section fixation consistent (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A02022-3); Caveat: Antibody staining has low consistency with RNA expression (HPA tissue IHC); Isoform / epitope: 2 isoforms; verify antibody epitope coverage (UniProt); Regulation: Up-regulated in memory CD8+ T cells (UniProt; by similarity). Evidence: UniProt P35558, HPA tissue IHC · Approved, HPA cell-line RNA · Highest expression in Hep-G2: 2.2 nTPM, Datasheet A02022-3, PMC11053060, PMC12128133. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PCK1/immunohistochemistry-ihc-guide.