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CYP1A2 / Cytochrome P450 1A2 · IHC design guide
Design Immunohistochemistry for CYP1A2
Use liver hepatocytes as the positive reference for CYP1A2 paraffin IHC; strong cytoplasmic staining is reported there (HPA tissue IHC). The catalog antibody PB9545 has an IHC range of 0.5–1 µg/ml (datasheet); assess unexpected staining in light of reported off-target binding (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CYP1A2 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 | Hepatocyte cytoplasm (HPA tissue IHC) | |
| Staining pattern | High cytoplasmic staining in hepatocytes (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet PB9545) | |
| Positive control | Liver | |
| 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 | Presumed off-target staining may mimic CYP1A2 (HPA tissue IHC) | |
| Regulation | Staining-linked regulation unreported (UniProt) | |
| Isoform / epitope | No annotated isoforms or transmembrane epitope split (UniProt) |
Section 1
Recommended CYP1A2 IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol (datasheet PB9545) with two published CYP1A2 chromogenic IHC protocols (PMC5503538; PMC12489364).
| Sample | Paraffin-embedded mouse liver tissue; fixative not specified (datasheet PB9545) |
| Fixation | Image fixative and duration unreported (datasheet PB9545); 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 PB9545); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet PB9545) |
| Primary antibody | Rabbit anti-CYP1A2, 0.5-1μg/ml (datasheet PB9545) |
| Primary incubation | Overnight at 4 °C (datasheet PB9545) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet PB9545) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | CYP1A2-positive staining in hepatocytes of liver (HPA tissue IHC: High). HPA tissue profile: High cytoplasmic expression exclusively in hepatocytes. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet PB9545); both published protocols used citrate pH 6.0 (PMC5503538; PMC12489364).
Section 2
What Is the Expected CYP1A2 Staining Pattern?
CYP1A2 should stain strongly in hepatocyte cytoplasm on liver IHC sections (HPA: high cytoplasmic expression exclusively in hepatocytes; IHC reliability Enhanced). Its annotated locations are the endoplasmic reticulum and microsome membranes, despite no annotated transmembrane segment (UniProt P05177: subcellular location and topology). Interpret the slide as a cellular cytoplasmic pattern; the supplied sources do not establish a distinctive organelle pattern resolvable by routine chromogenic IHC.
| Strong cytoplasmic staining in hepatocytes on a liver section. | This matches the reported positive tissue, cell type, intensity and compartment (HPA: liver hepatocytes High; high cytoplasmic expression exclusively in hepatocytes). Assess staining within recognizable hepatocytes and compare it with controls from the same staining run (general IHC practice). |
| Predominantly nuclear staining, with little convincing hepatocyte cytoplasmic signal. | A nuclear dominant pattern conflicts with the reported cytoplasmic staining and membrane associated localization (HPA: hepatocyte cytoplasmic expression; UniProt P05177: endoplasmic reticulum and microsome membranes). Treat it as suspect until controls and detection conditions are checked (general IHC practice). |
| Strong staining in nonhepatocyte cells or a tissue listed as not detected. | That distribution conflicts with the reported hepatocyte restricted pattern (HPA: high expression exclusively in hepatocytes; listed negative cells Not detected). Consider antibody cross reactivity or, for an enzyme based chromogen, endogenous detection activity; use appropriate controls to distinguish them (general IHC practice). |
| Widespread color over tissue and empty areas, obscuring cell boundaries. | Diffuse background prevents a confident call on hepatocyte cytoplasmic staining (HPA: expected high hepatocyte cytoplasmic expression). Review blocking, washing, detection and primary antibody concentration with control sections (general IHC practice); background alone does not establish CYP1A2 expression. |
| No convincing staining in a liver section containing hepatocytes. | This disagrees with the reported high hepatocyte signal (HPA: liver hepatocytes High). First check section quality, reagent function and control performance; then review retrieval and antibody conditions as general IHC troubleshooting. The supplied sources do not establish CYP1A2 specific fixation or retrieval sensitivity. |
💡Expected CYP1A2 appearanceCall the result positive when hepatocytes show strong cytoplasmic staining (HPA: liver hepatocytes High; cytoplasmic expression); isolated nuclear or nonhepatocyte signal is suspect against that reference pattern (HPA: high cytoplasmic expression exclusively in hepatocytes).
| Tissue and cell choice | Liver hepatocytes provide the documented positive reference (HPA: liver hepatocytes High). The listed negative cell types are reported as Not detected, including adipocytes and adrenal glandular cells (HPA: tissue IHC). A negative sample cannot replace a liver positive control when judging assay performance (general IHC practice). |
| Compartment used for scoring | Score cytoplasmic staining in hepatocytes as the reference pattern (HPA: tissue IHC profile). Endoplasmic reticulum and microsome membrane annotations support a cytoplasmic distribution (UniProt P05177: subcellular location); they do not define a distinct chromogenic substructure or a required granular appearance. |
| Evidence behind the reference pattern | The tissue IHC profile is rated Enhanced, with high consistency between staining and RNA data; presumed off target binding was observed and disregarded (HPA: reliability description). CAB016531 is listed as IHC Enhanced (HPA: antibodies). These summaries support the reference pattern, while a new run still needs its own controls (general IHC practice). |
| Antigen retrieval and target specific sensitivity | Review the validated assay conditions if signal is absent or excessive (general IHC practice). The supplied HPA and UniProt records give no CYP1A2 specific retrieval condition or fixation effect; the reported staining and topology cannot establish one. |
| Can ICC/IF use this IHC pattern as its reference? | Use it only as a cautious localization expectation: the ICC/IF summary says membrane, but provides no main location or cell line images (HPA: subcellular ICC/IF). The hepatocyte intensity and tissue pattern come from IHC (HPA: tissue IHC), so they do not establish an ICC/IF signal threshold. |
| Situation | Likely cause | Next action |
|---|---|---|
| Liver positive control is blank. | The result conflicts with reported high hepatocyte expression (HPA: liver hepatocytes High); an assay or section problem is possible (general IHC practice). | Check tissue integrity and that primary antibody, detection reagents and counterstain were applied; review retrieval and reagent conditions using the validated IHC assay (general IHC practice). Do not infer a CYP1A2 specific fixation failure from this result. |
| Hepatocyte staining is weak or patchy. | The observed result falls short of the reported high cytoplasmic pattern (HPA: liver hepatocytes High). Uneven processing or staining can also produce patchiness (general IHC practice). | Compare intact hepatocytes across the section and a positive control processed in the same run; inspect staining coverage, reagent function and assay conditions (general IHC practice). Avoid treating a weak run as a biological negative. |
| Nuclei dominate the signal. | Predominantly nuclear staining is discordant with hepatocyte cytoplasmic IHC and the membrane associated annotation (HPA: tissue IHC; UniProt P05177: subcellular location). | Review a no primary control and detection conditions, then score only convincing cytoplasmic signal in hepatocytes (general IHC practice; HPA: expected cytoplasmic pattern). |
| A listed negative tissue shows strong staining. | This conflicts with its reported Not detected cell population (HPA: tissue IHC negatives). Nonspecific antibody signal or endogenous chromogen activity may contribute (general IHC practice). | Confirm the stained cell type, compare with a no primary control and check any enzyme detection blocking step relevant to the method (general IHC practice). Interpret the negative tissue against the HPA cell specific entry. |
| Color appears broadly outside cells. | Background can obscure the expected hepatocyte cytoplasmic pattern (HPA: tissue IHC profile); incomplete blocking or washing can contribute (general IHC practice). | Inspect no primary and negative tissue controls; review blocking, washes and detection development under the validated assay conditions (general IHC practice). Reassess only when cell boundaries are clear. |
| Different runs give different staining intensity. | Run variation can change apparent chromogen intensity (general IHC practice); the HPA High designation describes the reference observation, not a numeric cutoff for every slide (HPA: liver hepatocytes High). | Run a liver positive control alongside test sections and compare within that run; keep scoring tied to hepatocyte cytoplasmic localization and control performance (HPA: tissue IHC pattern; general IHC practice). |
Experiment evidence
IHC & IF images showing CYP1A2 staining
PB9545 · IHCIHC analysis of CYP1A2 using anti-CYP1A2 antibody (PB9545). CYP1A2 was detected in a paraffin-embedded section of mouse liver tissue. Heat m
PB9545 · IHCIHC analysis of CYP1A2 using anti-CYP1A2 antibody (PB9545). CYP1A2 was detected in a paraffin-embedded section of rat liver tissue. Heat med
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000140505-CYP1A2/tissue/cerebral+cortex#imid_4087052
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000140505-CYP1A2/tissue/colon#imid_4086986
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000140505-CYP1A2/tissue/liver#imid_4086971
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000140505-CYP1A2/tissue/kidney#imid_4086980
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CYP1A2 IHC & IF
🧪Run liver first: hepatocytes should stain (HPA: High in hepatocytes). Run adipose tissue as the negative, where adipocytes are not detected (HPA: Not detected in adipocytes); on the liver slide, assess non-hepatocyte cells as candidate internal negatives against the control slides rather than assuming they lack CYP1A2.
Positive control tissue: Liver (Hepatocytes, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for CYP1A2; derive a cell-line control from the positive tissue's cell type (Hepatocytes) and confirm it by RNA or western blot first.
Technical controls: Include no-primary (secondary-only) and host-matched rabbit IgG controls, plus CYP1A2 knockout tissue if available. For liver IHC with the caption’s biotin-based DAB detection, block endogenous peroxidase and assess endogenous biotin background (selected PB9545 tissue-IHC caption: biotinylated secondary, SABC and DAB).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected PB9545 tissue-IHC caption does not state a fixative. The demonstrated paraffin-section procedure used heat-mediated EDTA retrieval at pH 8.0; retrieval requirements under other conditions are unreported (selected PB9545 tissue-IHC caption). The supplied evidence does not establish that frozen sections or IF/ICC are easier (HPA: no cell lines with ICC-IF images); endogenous biotin can complicate the caption’s biotin-based liver detection (selected PB9545 tissue-IHC caption: SABC).
HPA tissue IHC evidence for CYP1A2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High 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 |
|---|---|---|---|---|
| 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 → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced CYP1A2 IHC Tips
Troubleshoot CYP1A2 staining in paraffin sections by checking retrieval, hepatocyte localisation, controls, and scoring against the documented IHC result.
What should I change when CYP1A2 staining is weak after antigen retrieval?
Use heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin sections stained with PB9545 (datasheet PB9545). The mouse liver caption documents this retrieval, followed by 10% goat serum blocking and 1 μg/ml primary antibody overnight at 4°C (datasheet PB9545). If hepatocyte cytoplasm remains faint, confirm complete deparaffinisation and consistent heating before comparing a cautiously titrated alternative retrieval condition on adjacent sections (standard IHC practice; HPA: high cytoplasmic expression in hepatocytes). Keep detection chemistry and imaging settings consistent across conditions so increased DAB intensity is not mistaken for improved epitope access (standard IHC practice).
How can I assess whether fixation caused weak CYP1A2 staining?
The selected paraffin-section image does not state its fixative, and target-specific fixation sensitivity is unknown (datasheet PB9545: fixative not stated). Record the fixative, fixation duration, and tissue thickness for each block, then compare matched liver sections processed under controlled conditions (standard IHC practice; UniProt P05177: liver specificity). Start those comparisons with heat-mediated EDTA retrieval at pH 8.0 and 1 μg/ml antibody overnight at 4°C, matching the documented staining conditions (datasheet PB9545). Include a liver control in every run and assess tissue morphology before attributing patchy or weak hepatocyte staining to fixation (HPA: high hepatocyte cytoplasmic expression; standard IHC practice).
Where should a credible CYP1A2 IHC signal appear?
Look for cytoplasmic staining in hepatocytes, the cell population with high expression in the tissue IHC profile (HPA: high cytoplasmic expression exclusively in hepatocytes). CYP1A2 is associated with endoplasmic reticulum and microsome membranes, so a cytoplasmic pattern fits its annotated location (UniProt P05177: subcellular location). Its record annotates no transmembrane segment; do not require a sharp plasma-membrane outline to accept staining (UniProt P05177: topology). Compare adjacent hepatocytes at similar section depth and inspect the haematoxylin counterstain for intact morphology before scoring DAB intensity (standard IHC practice). Predominantly nuclear or extracellular signal warrants a specificity and background check (UniProt P05177: subcellular location; standard IHC practice).
Could isoforms or epitope accessibility explain discordant CYP1A2 staining?
The supplied record lists 0 isoforms, so an isoform switch is not an established explanation for discordant staining here (UniProt P05177: isoforms). It annotates a glycosylation site at residue 69 and no transmembrane segment, but does not identify the catalog antibody’s epitope or its membrane-facing side (UniProt P05177: glycosylation and topology; datasheet PB9545: epitope not supplied). Accordingly, test epitope accessibility empirically with the documented EDTA retrieval at pH 8.0 and matched liver controls (datasheet PB9545; standard IHC practice). If staining remains discordant, use an independently validated antibody or another orthogonal measure before assigning the difference to CYP1A2 biology (standard IHC practice).
How should I investigate a discordant CYP1A2 immunofluorescence result?
Treat IF as a separate comparison with the chromogenic IHC result: the supplied PB9545 image documents paraffin-section IHC, while IF validation is not supplied (datasheet PB9545). Multiplex CYP1A2 with a validated hepatocyte marker and check whether its signal occupies hepatocyte cytoplasm (HPA: high cytoplasmic expression in hepatocytes; standard IF practice). Choose a fluorophore in a channel with low measured liver autofluorescence and include an unstained section for comparison (standard IF practice). Because the antibody epitope’s membrane-facing side is unspecified, compare permeabilised and unpermeabilised preparations with matched controls rather than assuming which treatment exposes it (UniProt P05177: ER membrane association; datasheet PB9545: epitope not supplied; standard IF practice).
What should I check when liver sections show diffuse DAB background?
First compare the suspect section with a no-primary control and the expected hepatocyte cytoplasmic pattern (standard IHC practice; HPA: high hepatocyte cytoplasmic expression). The selected protocol used 10% goat serum, a biotinylated secondary antibody, streptavidin-biotin detection, and DAB (datasheet PB9545). Verify adequate serum blocking and washing, then check for endogenous peroxidase activity and biotin-related signal with appropriate controls for that detection system (standard IHC practice). If background persists, titrate the primary around the documented 1 μg/ml condition while keeping retrieval at EDTA pH 8.0 and detection timing consistent (datasheet PB9545; standard IHC practice).
How should I quantify CYP1A2 staining across liver sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define hepatocytes as the scoring population and record the percentage positive plus staining intensity within intact, comparable tissue regions (HPA: high expression in hepatocytes; standard IHC practice). An H-score combines the percentages at intensity grades 0–3 into a 0–300 value; apply one threshold and scoring rubric to every section (standard IHC practice). Normalise cell counts or stained area to the number of evaluable hepatocytes or hepatocyte area, and report excluded damaged regions (standard IHC practice). Keep section thickness, EDTA retrieval at pH 8.0, DAB development, and image settings consistent before comparing scores (datasheet PB9545; standard IHC practice).
How can I distinguish true CYP1A2 staining from an artefact?
A credible result concentrates in hepatocyte cytoplasm within intact liver tissue, consistent with the tissue profile and ER or microsome association (HPA: high cytoplasmic expression exclusively in hepatocytes; UniProt P05177: subcellular location). Question predominantly nuclear, extracellular, or nonhepatocyte staining, particularly when it persists in a no-primary control (UniProt P05177: subcellular location; standard IHC practice). Inspect section edges and necrotic areas separately, since uneven staining there can reflect preparation artefacts rather than interpretable cellular signal (standard IHC practice). With the documented biotin-based DAB method, check endogenous peroxidase and biotin-related background before calling diffuse brown staining CYP1A2 positive (datasheet PB9545; standard IHC practice).
Boster reagents
Best CYP1A2 / Cytochrome P450 1A2 IHC Antibodies
PB9545 has paraffin-section IHC images from mouse and rat liver, human liver, and human liver cancer tissue (PB9545 image captions). M00598 lists human IF/ICC applications, with no supplied IF image (catalog: M00598).
Real IHC data
Anti-Cytochrome P450 1A2/CYP1A2 Antibody ®
Cat # PB9545
PB9545 is the rendered IHC card, with paraffin-section images from mouse and rat liver, human liver, and human liver cancer tissue (PB9545 image captions). M00598 lists human IF/ICC applications, but no IF image is supplied (catalog: M00598).
Which to pick: Choose PB9545 for paraffin-section IHC: its mouse liver image used 1 μg/ml antibody after EDTA retrieval (PB9545 image caption); the fixative is unreported (PB9545 image caption). Choose M00598 for human IF/ICC because those applications are listed for this rabbit monoclonal, though no IF image is supplied (catalog: M00598). For human, mouse, or rat tissue IHC, choose PB9545 based on its listed reactivity and paraffin-section images (catalog: PB9545; PB9545 image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P05177 (CP1A2_HUMAN, Cytochrome P450 1A2).
- Human Protein Atlas. CYP1A2 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. CYP1A2 subcellular location (ICC-IF): Membrane.
- Human Protein Atlas. CYP1A2 antibody validation summary (1 antibodies).
- The associations of genetic polymorphisms in CYP1A2 and CYP3A4 with clinical outcomes of breast cancer patients in northern China. Oncotarget 2017 — PMC5503538.
- CYP1A2 expression and activity in a large panel of human nonneoplastic surgical liver samples: Influence of genetics, lifestyle, and other factors. Drug metabolism and disposition: the biological fate of chemicals 2025 — PMC12489364.
- Air-ventilated normothermic machine perfusion alleviates hepatic injury from DCD rat through CYP1A2. Heliyon 2023 — PMC10465863.
- The Intervention and Mechanism of Action for Aloin against Subchronic Aflatoxin B1 Induced Hepatic Injury in Rats. International journal of molecular sciences 2021 — PMC8584096.
- PubMed PMID:3755823 — UniProt-cited evidence.
- PubMed PMID:3462722 — UniProt-cited evidence.
- PubMed PMID:2575218 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CYP1A2 (Cytochrome P450 1A2). Expected localisation Hepatocyte cytoplasm (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet PB9545). Validated IHC antibody: PB9545 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Liver (Hepatocytes); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded mouse liver tissue; fixative not specified (datasheet PB9545); 2. Fixation: Image fixative and duration unreported (datasheet PB9545); 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 PB9545); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet PB9545); 8. Primary antibody: Rabbit anti-CYP1A2, 0.5-1μg/ml (datasheet PB9545); 9. Primary incubation: Overnight at 4 °C (datasheet PB9545). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Presumed off-target staining may mimic CYP1A2 (HPA tissue IHC); Isoform / epitope: No annotated isoforms or transmembrane epitope split (UniProt); Regulation: Staining-linked regulation unreported (UniProt). Evidence: UniProt P05177, HPA tissue IHC · Enhanced, HPA ICC-IF · Membrane, Datasheet PB9545, PMC5503538, PMC12489364. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CYP1A2/immunohistochemistry-ihc-guide.