This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
PRKG2 / cGMP-dependent protein kinase 2 · IHC design guide
Design Immunohistochemistry for PRKG2
Plan chromogenic PRKG2 IHC in paraffin sections using high-staining glandular cells in small intestine, appendix or gallbladder as reference material (HPA tissue IHC). This guide covers fixation consistency and interpretation of observed cytoplasmic staining (HPA tissue IHC) alongside the annotated apical membrane location (UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PRKG2 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 | Glandular cells show general cytoplasmic staining (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A05103) | |
| Positive control | Appendix+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 | Staining has low concordance with RNA data (HPA tissue IHC) | |
| Regulation | Tissue-dependent expression (UniProt) | |
| Isoform / epitope | 2 isoforms; map the epitope before comparing staining (UniProt) |
Section 1
Recommended PRKG2 IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol (datasheet A05103) with one published PRKG2 protocol in rat carotid artery sections (PMC13446705).
| Sample | Paraffin-embedded human tonsil tissue; fixative not specified (datasheet A05103) |
| Fixation | Image fixative and duration unreported (datasheet A05103); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Tris-EDTA pH 9.0 (datasheet A05103); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% normal serum of the secondary host, 30 min, room temperature (standard) |
| Primary antibody | Rabbit anti-PRKG2, 1:100-1:300 (datasheet A05103) |
| Primary incubation | Overnight at 4 °C (standard) |
| Detection | HRP-polymer secondary, DAB chromogen 5–10 min (standard) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | PRKG2-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with Tris-EDTA pH 9.0 heat retrieval for the catalog antibody (datasheet A05103); citrate pH 6.0 is the published alternative (PMC13446705).
Section 2
What Is the Expected PRKG2 Staining Pattern?
PRKG2 is annotated at the apical cell membrane without a transmembrane segment (UniProt Q13237 topology). In paraffin sections, expect staining in glandular cells of appendix, gallbladder and small intestine, and respiratory epithelial cells of bronchus (HPA: High). HPA also describes a general cytoplasmic pattern (HPA: tissue IHC). Interpret the pattern cautiously: HPA rates its IHC data Approved but reports low agreement with RNA expression and pending external verification (HPA: reliability).
| Epithelial cytoplasmic staining, sometimes concentrated toward the apical surface, in the listed positive tissues. | This fits HPA's general cytoplasmic IHC profile and UniProt's apical membrane annotation (HPA: tissue IHC; UniProt Q13237 localisation). Score the observed compartment and cell type separately; an apical accent is plausible, but HPA does not establish it as a required feature of every positive gland. |
| Predominantly nuclear staining, with little epithelial cytoplasmic signal. | That compartment is discordant with the supplied localisation evidence (HPA: general cytoplasmic expression; UniProt Q13237: apical cell membrane). Treat an isolated nuclear pattern as suspect, then compare it with a positive tissue and appropriate detection controls before calling it PRKG2 (general IHC practice). |
| Strong staining mainly in fibroblasts or splenic red pulp cells. | Those cells are reported at Low staining, whereas several glandular and respiratory epithelial populations are High (HPA: tissue IHC). A dominant signal in these cells warrants a specificity check; cross-reactivity or endogenous detection activity are possibilities, not conclusions from appearance alone (general IHC practice). |
| Broad, nearly uniform colour across cells and tissue spaces. | A uniform haze obscures the cell and compartment pattern needed for interpretation (general IHC practice). Compare with a section lacking primary antibody and inspect blocking, detection and wash steps; those checks distinguish background from a tissue pattern without presuming a PRKG2-specific cause (general IHC practice). |
| No convincing staining in appendix, bronchus, gallbladder or small intestine. | Each has a High-staining epithelial population in the supplied HPA IHC record (HPA: tissue IHC). An absent signal therefore makes the run or specimen worth checking, although HPA's low RNA–staining consistency means one negative section cannot, by itself, settle antibody specificity (HPA: reliability). |
💡Expected PRKG2 appearanceA credible positive is distinct cytoplasmic staining in the specified glandular or respiratory epithelial cells, potentially accentuated apically, with High staining reported by HPA; dominant nuclear, low-cell-type or uniform background staining is suspect (HPA: tissue IHC; UniProt Q13237 localisation; general IHC practice).
| Compartment and topology (UniProt Q13237) | UniProt places PRKG2 at the apical cell membrane and reports no transmembrane segment; HPA describes general cytoplasmic IHC staining (UniProt Q13237 topology; HPA: tissue IHC). Evaluate both descriptions against the visible epithelial pattern. Neither source supplies a rule that every positive paraffin section must show a sharp membrane outline. |
| Choice of comparison tissue (HPA: tissue IHC) | Appendix, bronchus, gallbladder and small intestine contain specified High-staining epithelial populations; fibroblasts in soft tissue and splenic red pulp cells are Low (HPA: tissue IHC). Compare like cell types when judging a run. No tissue in the supplied HPA list is designated negative (HPA: negative list empty). |
| Strength of validation (HPA: antibodies and reliability) | HPA lists two rabbit polyclonal antibodies, HPA007386 and CAB018739, as IHC Approved; it reports low agreement between antibody staining and RNA expression and says external verification is pending (HPA: antibodies; HPA: reliability). These data support cautious pattern comparison, not an assertion of independently reproduced or definitive specificity. |
| Isoforms and antigen features (UniProt Q13237) | UniProt records two PRKG2 isoforms and several phosphorylated residues, including Ser110, Ser117, Ser431 and Thr609 (UniProt Q13237). The supplied record gives no antibody epitope or isoform selectivity, so these facts cannot predict which isoform a stain detects or whether phosphorylation changes its IHC signal. |
| Can this pattern be carried over to IF/ICC? (HPA: subcellular and antibodies) | The supplied HPA ICC-IF record has no main location or cell-line images, and neither listed antibody has an ICC validation entry (HPA: subcellular; HPA: antibodies). Use the tissue IHC pattern as context only; the supplied evidence does not establish an IF/ICC staining pattern or support an IF/ICC protocol choice. |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in a listed High-staining tissue. | The run may have a specimen or detection problem; a single blank section does not identify the cause (general IHC practice; HPA: tissue IHC). | Confirm the expected epithelial cells are present, review the catalog antibody's IHC-P instructions, and check the run's positive and detection controls (general IHC practice). |
| Signal appears chiefly nuclear. | The pattern conflicts with the supplied cytoplasmic and apical annotations (HPA: tissue IHC; UniProt Q13237 localisation). | Recheck compartment assignment against the counterstain and a positive tissue; assess primary-omission background before interpreting the nuclear signal (general IHC practice). |
| Fibroblasts or red pulp cells dominate the staining. | Those populations are Low in the supplied HPA record; specificity or detection background may need investigation (HPA: tissue IHC; general IHC practice). | Compare epithelial and low-staining cells on matched sections, then inspect primary-omission and detection controls (HPA: tissue IHC; general IHC practice). |
| Diffuse chromogen obscures cell borders. | Nonspecific detection or inadequate washing can produce background in chromogenic IHC (general IHC practice). | Inspect a primary-omission control and review blocking, wash and detection steps before scoring compartment or intensity (general IHC practice). |
| Cytoplasmic signal is present but lacks a crisp apical rim. | HPA reports general cytoplasmic expression, while UniProt annotates apical membrane localisation; the records do not require an apical rim in every section (HPA: tissue IHC; UniProt Q13237). | Judge cell identity and background first, record the observed distribution, and avoid rejecting an epithelial cytoplasmic pattern solely for this feature (HPA: tissue IHC; general IHC practice). |
| Staining varies between sections or tissues. | Cell composition and assay performance can affect IHC comparisons; HPA also flags low agreement between staining and RNA data (general IHC practice; HPA: reliability). | Compare the same annotated cell populations, use run controls, and report variation without converting the supplied Low entries into validated negatives (HPA: tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing PRKG2 staining
A05103 · IHCImmunohistochemical analysis of paraffin-embedded human tonsil. 1, Antibody was diluted at 1:200 (4° overnight). 2, Tris-EDTA, pH9.0 was use
A30481 · IHCImmunohistochemical analysis of paraffin-embedded human tonsil. 1, Antibody was diluted at 1:200(4° overnight). 2, Tris-EDTA,pH9.0 was used
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000138669-PRKG2/tissue/cerebral+cortex#imid_5029844
HPA · Small intestineHuman Protein Atlas IHC, Small intestine. Source: https://www.proteinatlas.org/ENSG00000138669-PRKG2/tissue/small+intestine#imid_5029745
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000138669-PRKG2/tissue/colon#imid_5029778
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000138669-PRKG2/tissue/liver#imid_5029771
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PRKG2 IHC & IF
🧪Run small intestine first; glandular cells should stain (HPA: High in small-intestinal glandular cells). HPA detects PRKG2 in all 45 scored tissues, so use no-primary and isotype controls in place of a negative tissue; adjacent nonglandular cells should show only background in those control sections, but are not validated target-negative cells (HPA: no negative tissue rows).
Positive control tissue: Appendix (Glandular cells, HPA High)
Negative control tissue: None in HPA: PRKG2 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 carries no ICC-IF cell line for PRKG2; derive a cell-line control from the positive tissue's cell type (Glandular cells) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only section and an irrelevant antibody matched to the primary antibody’s host species and immunoglobulin class; use PRKG2 knockout tissue or peptide competition, if available, to test target specificity (standard IHC practice). Check endogenous peroxidase and biotin background in small-intestinal sections before interpreting chromogenic signal (standard IHC practice).
⚠️Feasibility: A PRKG2-specific fixation window or fixation effect is unreported, and the selected A05103 paraffin-section caption does not state a fixative (selected SKU caption: fixative not stated). The reported IHC conditions use Tris-EDTA retrieval at pH 9.0 and primary antibody at 1:200 overnight at 4°C; whether retrieval is required is unreported (selected SKU caption). The supplied evidence does not establish frozen sections or IF/ICC as easier, and intestinal endogenous enzyme or biotin background should be assessed on control sections (HPA: no ICC-IF images; standard IHC practice).
HPA tissue IHC evidence for PRKG2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low consistency between antibody staining and RNA expression data. Pending external verification.). 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 |
|---|---|---|---|---|
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Gallbladder | Glandular cells | High | Protein (IHC) | HPA → |
| Small intestine | Glandular cells | High | Protein (IHC) | HPA → |
| Adipose tissue | Adipocytes | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: PRKG2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced PRKG2 IHC Tips
Troubleshoot PRKG2 staining in paraffin sections by checking retrieval, cellular distribution, controls, and scoring before interpreting chromogenic signal.
Which retrieval condition should I start with for PRKG2 paraffin IHC?
Use heat-mediated Tris-EDTA at pH 9.0 for paraffin sections (datasheet A05103). The catalog antibody’s paraffin-section image used this retrieval condition, followed by primary antibody at 1:200 overnight at 4°C (datasheet A05103). If staining is weak, check that sections reached the intended retrieval temperature and that the buffer retained its pH throughout heating (standard IHC practice). Compare any later retrieval changes on adjacent sections with identical antibody and detection settings, because altered retrieval can also increase nonspecific staining (standard IHC practice). Include a consistently stained reference section in each run to distinguish retrieval variation from sample variation (standard IHC practice).
How should I troubleshoot fixation when PRKG2 staining varies between paraffin samples?
The catalog image identifies paraffin-embedded human tonsil but does not state its fixative (datasheet A05103). Consequently, PRKG2-specific sensitivity to fixative type or fixation duration is unknown from the supplied evidence (datasheet A05103). Record each sample’s fixative and processing history, then compare sections with similar handling before changing retrieval or antibody concentration (standard IHC practice). Inspect morphology alongside signal: poor preservation, uneven staining, and damaged edges can indicate processing problems without establishing a PRKG2-specific fixation effect (standard IHC practice). Use an internally consistent reference section and the stated pH 9.0 retrieval condition while assessing fixation-associated variation (datasheet A05103; standard IHC practice).
Should PRKG2 staining be apical, cytoplasmic, or both?
Expect possible apical membrane-associated signal because PRKG2 is annotated at the apical cell membrane, despite having no transmembrane segment (UniProt Q13237 localisation and topology). A tissue-IHC survey instead describes general cytoplasmic expression, so score apical and cytoplasmic staining separately rather than assuming either pattern is definitive (HPA: tissue IHC profile). Examine glandular cells in appendix or small intestine and respiratory epithelial cells in bronchus as reported high-staining contexts (HPA: High in those cell types). Confirm that signal follows intact cellular boundaries or cytoplasm rather than luminal debris or section edges (standard IHC practice). The survey notes low consistency with RNA expression and pending external verification, which limits localisation certainty (HPA: reliability description).
Could isoforms or epitope accessibility explain inconsistent PRKG2 staining?
PRKG2 has 2 annotated isoforms, but the supplied antibody caption does not identify the recognized epitope or establish isoform coverage (UniProt Q13237 isoforms; datasheet A05103). Its kinase domain spans residues 453–711, and documented modified residues include Ser-110, Ser-117, Ser-431, and Thr-609 (UniProt Q13237 domains and modified residues). Those annotations alone cannot show whether fixation, retrieval, or phosphorylation masks this antibody’s epitope (UniProt Q13237; datasheet A05103). Check the antibody’s epitope documentation before interpreting differential staining as an isoform or phosphorylation change (standard IHC practice). If available, compare an independently validated PRKG2 reagent and appropriate controls on adjacent sections under matched processing conditions (standard IHC practice).
How can I assess PRKG2 by IF alongside the paraffin IHC result?
Treat IF as a separate assay: the supplied catalog image documents paraffin chromogenic IHC, while the HPA subcellular record lists no ICC/IF images (datasheet A05103; HPA: subcellular record). Multiplex PRKG2 with a marker identifying the expected glandular or respiratory epithelial cell population, and inspect each channel independently before interpreting overlap (HPA: high-staining cell types; standard IF practice). Choose fluorophores whose emission can be distinguished from the sample’s autofluorescence, using unstained and single-label controls (standard IF practice). Because PRKG2 is annotated at the apical membrane without a transmembrane segment, select permeabilisation according to the antibody epitope’s documented accessibility and compare permeabilised with untreated sections if that accessibility is unknown (UniProt Q13237 topology; standard IF practice).
What should I change when PRKG2 chromogenic staining is diffuse or patchy?
First compare the primary-omission control with the stained section to identify signal arising from the detection system (standard IHC practice). The catalog image used primary antibody at 1:200 overnight at 4°C and secondary antibody at 1:200 for 45 minutes at room temperature; use those documented settings as the comparison point (datasheet A05103). For peroxidase detection, check the endogenous peroxidase block, nonspecific protein block, washes, and DAB development on matched sections (standard chromogenic IHC practice). Examine whether patchiness follows tissue folds, drying, damaged edges, or uneven reagent coverage rather than intact cells (standard IHC practice). Adjust one workflow variable at a time and retain the same reference section for comparison (standard IHC practice).
How should I quantify PRKG2 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the scored cell population and compartment before reviewing groups, because reported staining includes glandular or respiratory epithelial cells and both apical and general cytoplasmic descriptions (HPA: tissue IHC profile; UniProt Q13237 localisation). For a cellular H-score, multiply each intensity category, 0–3, by its percentage of cells and sum to a 0–300 score (standard IHC scoring practice). Alternatively, report the percentage of positive cells or positive-cell density per mm² of evaluable tissue (standard IHC scoring practice). Normalize counts to the same annotated cell population or evaluable epithelial area, excluding folds, necrosis, and section edges (standard IHC practice). Keep exposure, threshold, and scoring rules fixed across batches (standard IHC practice).
How do I distinguish convincing PRKG2 signal from IHC artefact?
Give greatest weight to reproducible staining in intact glandular or respiratory epithelial cells, which are reported high-staining populations, while checking for the annotated apical membrane distribution (HPA: high-staining cell types; UniProt Q13237 localisation). General cytoplasmic staining has also been reported, so compartment alone cannot establish specificity (HPA: tissue IHC profile). Signal concentrated at cut edges, folds, necrotic areas, or luminal debris warrants review as possible artefact (standard IHC practice). Compare primary-omission and endogenous peroxidase controls when DAB signal appears in unexpected cells or compartments (standard chromogenic IHC practice). Interpret discordant patterns cautiously because the tissue-IHC survey reports low agreement with RNA expression and awaits external verification (HPA: reliability description).
Boster reagents
Best PRKG2 / cGMP-dependent protein kinase 2 IHC Antibodies
Two anti-PRKG2 antibodies have human tonsil paraffin-section IHC images (catalog: A05103, A30481); both list IF and Human, Mouse, Rat reactivity (catalog: applications/reactivity).
Real IHC data
Anti-cGKII PRKG2 Antibody
Cat # A05103
Real IHC data
Anti-CGK 2 Antibody
Cat # A30481
A05103 will render with a paraffin-section human tonsil IHC image using primary antibody at 1:200 and Tris-EDTA retrieval at pH 9.0 (A05103 image caption). A30481 will render with its own paraffin-section human tonsil IHC image using the same reported dilution and retrieval conditions (A30481 image caption).
Which to pick: For tissue IHC, either SKU has its own paraffin-section image; the fixative is unreported for both (A05103 and A30481 image captions). For IF/ICC, choose A30481 because it lists both applications, while A05103 lists IF only; neither has an IF image in the payload (catalog: applications/images). For Human, Mouse, or Rat work, both list reactivity and are rabbit polyclonals, but their pictured IHC evidence is human tonsil only (catalog: reactivity/host/clone; A05103 and A30481 image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q13237 (KGP2_HUMAN, cGMP-dependent protein kinase 2).
- Human Protein Atlas. PRKG2 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. PRKG2 subcellular location (ICC-IF): Highest expression in HEL: 17.2 nTPM.
- Human Protein Atlas. PRKG2 antibody validation summary (2 antibodies).
- Vitamin B12 combined with methylene blue alleviates experimental septic shock and is associated with modulation of KCNMB1 and the cGMP-PRKG pathway. PloS one 2026 — PMC13446705.
- The cGMP-Dependent Protein Kinase 2 Contributes to Cone Photoreceptor Degeneration in the Cnga3-Deficient Mouse Model of Achromatopsia. International journal of molecular sciences 2020 — PMC7793084.
- PubMed PMID:8607838 — UniProt-cited evidence.
- PubMed PMID:7498513 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PRKG2 (cGMP-dependent protein kinase 2). Expected localisation General cytoplasmic staining (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A05103). Validated IHC antibody: A05103 at 1:100-1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded human tonsil tissue; fixative not specified (datasheet A05103); 2. Fixation: Image fixative and duration unreported (datasheet A05103); 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: Tris-EDTA pH 9.0 (datasheet A05103); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% normal serum of the secondary host, 30 min , room temperature (standard); 8. Primary antibody: Rabbit anti-PRKG2, 1:100-1:300 (datasheet A05103); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Staining has low concordance with RNA data (HPA tissue IHC); Isoform / epitope: 2 isoforms; map the epitope before comparing staining (UniProt); Regulation: Tissue-dependent expression (UniProt). Evidence: UniProt Q13237, HPA tissue IHC · Approved, HPA cell-line RNA · Highest expression in HEL: 17.2 nTPM, Datasheet A05103, PMC13446705. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PRKG2/immunohistochemistry-ihc-guide.