PRKAR1A / cAMP-dependent protein kinase type I-alpha regulatory subunit · IHC design guide

Design Immunohistochemistry for PRKAR1A

Plan PRKAR1A staining in paraffin sections using the variable membranous and cytoplasmic tissue pattern as a reference (HPA tissue IHC). Compare cell types within each section and use consistent fixation when assessing staining intensity.

Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use

Immunohistochemistry protocol sheet for PRKAR1A (IHC for PRKAR1A): expected localisation Membranous and cytoplasmic tissue staining (HPA tissue IHC), antibody A00699-1, validated IHC image, and IHC protocol steps — Printable **PRKAR1A** IHC protocol sheet — expected localisation Membranous and cytoplasmic tissue staining (HPA tissue IHC), antibody A00699-1, controls and protocol steps. Open the full PRKAR1A IHC guide →

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PRKAR1A 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	Membranous and cytoplasmic tissue staining (HPA tissue IHC)
	Staining pattern	Variable membrane and cytoplasm staining, including glandular cells (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A00699-1)
	Positive control ⓘ	Adrenal gland+4 more · see all
	Negative control ⓘ	Adipose tissue+4 more · see all

Important caveats

Reasons your staining may differ from the expected pattern.

	Fixation	Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A00699-1)
	Caveat	Staining levels vary among tissues (HPA tissue IHC)
	Regulation	Regulatory-chain expression varies by tissue (UniProt)
	Isoform / epitope	2 isoforms; antibody epitope coverage is unknown (UniProt)

Section 1

Recommended PRKAR1A IHC & IF Protocols

The catalog antibody protocol uses EDTA retrieval (datasheet A00699-1). The published IHC protocols below report methods for odontogenic tumors, lung adenocarcinoma, and fibrolamellar carcinoma (PMC4439291; PMC5171641; PMC6151295).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded rat testis tissue; fixative not specified (datasheet A00699-1)
Fixation	Image fixative and duration unreported (datasheet A00699-1); 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 A00699-1); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A00699-1)
Primary antibody	Rabbit anti-PRKAR1A, 0.5-1μg/ml (datasheet A00699-1)
Primary incubation	Overnight at 4 °C (datasheet A00699-1)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A00699-1)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	PRKAR1A-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: Membranous and cytoplasmic expression at variable levels in most tissues. No signal in the no-primary control.

💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet A00699-1). Published protocols also report heated Trilogy solution or steam retrieval (PMC4439291; PMC6151295).

Section 2

What Is the Expected PRKAR1A Staining Pattern?

PRKAR1A should show variable membranous and cytoplasmic staining across tissues (HPA tissue IHC: Approved, pending external verification). Medium staining is reported in adrenal glandular cells, cortical and hippocampal neurons, and cardiomyocytes (HPA tissue IHC). Cell membrane association is consistent with UniProt, although PRKAR1A has no transmembrane segment (UniProt P10644: subcellular location and topology). Interpret staining by cell type and compartment, since some cells within otherwise sampled tissues are not detected (HPA tissue IHC).

What am I looking at on my slide?
Membranous and cytoplasmic staining in adrenal glandular cells, neurons, or cardiomyocytes.	This matches the reported distribution; these cell populations reach Medium staining in the HPA examples (HPA tissue IHC). Assess each population separately, since expression varies by tissue and cell type (HPA tissue IHC).
Predominantly nuclear staining with little corresponding cytoplasmic or membranous signal.	Treat this as a discordant compartment pattern requiring control review: HPA tissue IHC reports membranous and cytoplasmic expression, while HPA ICC-IF reports approved cytosolic localization (HPA tissue IHC; HPA subcellular). Nuclear signal alone does not establish PRKAR1A localization.
Strong staining in adipocytes, marrow hematopoietic cells, or lung alveolar cells.	These specific populations were Not detected in the HPA tissue examples (HPA tissue IHC). Review cell identification and staining controls; a discordant signal may reflect cross-reactivity or endogenous detection activity (general IHC practice). An HPA non-detection is assay-specific, not proof of biological absence.
Diffuse brown deposit across tissue, stroma, and the no-primary control.	A control that develops color without primary antibody suggests background from the detection system, including endogenous activity, rather than a cell-specific PRKAR1A result (general chromogenic IHC practice). Interpret any apparent positive cells only after the control background is resolved.
No discernible signal in adrenal glandular cells or cortical neurons.	Both are reported at Medium intensity in HPA tissue IHC, so a blank result warrants assay troubleshooting (HPA tissue IHC). Check section quality, retrieval, antibody conditions, and detection with controls (general IHC practice); the supplied sources do not establish PRKAR1A-specific fixation sensitivity.

💡Expected PRKAR1A appearanceCall a result consistent when membranous and cytoplasmic staining is visible at roughly Medium intensity in an HPA Medium population, such as adrenal glandular cells; isolated nuclear staining or signal across a no-primary control is suspect (HPA tissue IHC; general IHC practice).

How each factor affects the staining
Tissue and cell choice	HPA reports Medium staining in selected glandular cells, neurons, cardiomyocytes, germinal center cells, and ciliary tips, but Low or Not detected levels in other specified populations (HPA tissue IHC). Choose a control by named cell population rather than organ alone.
Membrane association	UniProt assigns cell membrane localization and reports AKAP19-mediated targeting to the plasma membrane, with no transmembrane segment (UniProt P10644: subcellular location, subunit, topology). Membranous signal can accompany cytoplasmic staining (HPA tissue IHC).
Antibody evidence	HPA lists IHC as Approved for HPA049979 and CAB019378; the tissue profile is Approved but pending external verification (HPA antibodies; HPA tissue IHC). These labels support a reference pattern, not automatic validation of a different catalog antibody.
Isoform coverage	UniProt lists 2 isoforms (UniProt P10644: isoforms). Epitope location and isoform coverage are not supplied; confirm the chosen antibody's recognition details before interpreting a missing cell population as isoform-specific.
Can ICC/IF confirm the compartment?	HPA reports approved cytosolic localization in ICC-IF images from A-431, U-251MG, and U2OS (HPA subcellular). Use that as a localization comparison; it does not supply an IHC staining protocol or make ICC-IF and tissue IHC patterns interchangeable.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Positive tissue appears blank.	The run may have failed, or the evaluated cells may differ from the HPA Medium population (HPA tissue IHC; general IHC practice).	Locate the named cells first, then check a known-positive section, primary-antibody conditions, retrieval, and detection controls (general IHC practice). Do not attribute the result to PRKAR1A fixation sensitivity without evidence.
Signal appears mainly in nuclei.	The pattern conflicts with HPA's membranous and cytoplasmic tissue profile and approved cytosolic ICC-IF location (HPA tissue IHC; HPA subcellular).	Compare a positive reference tissue and no-primary control; reassess compartment boundaries and antibody specificity before scoring nuclear signal (general IHC practice).
Brown signal covers nearly every structure.	Diffuse deposit may arise from nonspecific binding or endogenous chromogenic detection activity (general IHC practice).	Inspect no-primary and detection-only controls; optimize blocking, washes, and detection conditions before interpreting cell-specific staining (general IHC practice).
Adipocytes or alveolar cells appear strongly positive.	Those populations are Not detected in the HPA examples; misidentified cells, cross-reactivity, or detection background are possible (HPA tissue IHC; general IHC practice).	Verify the cell type on the counterstained section and compare controls and another reported positive population before accepting the signal (general IHC practice).
Signal is weaker than expected in a chosen control.	HPA intensity varies by population: Purkinje cells and thyroid glandular cells are Low, while cortical neurons are Medium (HPA tissue IHC).	Check the exact population and use an HPA Medium example for a clearer positive reference; assess intensity against adjacent tissue and controls (HPA tissue IHC; general IHC practice).
ICC-IF and paraffin IHC appear different.	HPA ICC-IF reports cytosol, whereas HPA tissue IHC reports membranous and cytoplasmic staining; the observations come from different preparations (HPA subcellular; HPA tissue IHC).	Interpret each assay against its own HPA reference and controls. For the paraffin-section decision, prioritize the tissue IHC cell population and pattern (HPA tissue IHC; general IHC practice).

Source: UniProt P10644 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing PRKAR1A staining

IHC analysis of PRKAR1A using anti-PRKAR1A antibody (A00699-1). PRKAR1A was detected in a paraffin-embedded section of rat testis tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1 μg/ml rabbit anti-PRKAR1A Antibody (A00699-1) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A00699-1 · IHCIHC analysis of PRKAR1A using anti-PRKAR1A antibody (A00699-1). PRKAR1A was detected in a paraffin-embedded section of rat testis tissue. He

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000108946-PRKAR1A/tissue/cerebral+cortex#imid_14122070

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000108946-PRKAR1A/tissue/colon#imid_14121988

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000108946-PRKAR1A/tissue/liver#imid_14121989

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000108946-PRKAR1A/tissue/kidney#imid_14121982

HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody CAB019378; green = PRKAR1A, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

Real IHC / IF data behind the staining-pattern expectations in this section.

Sample controls for PRKAR1A IHC & IF

🧪Run adrenal gland first; glandular cells should stain (HPA: Medium in adrenal gland glandular cells). Use adipose tissue as the negative comparator (HPA: Not detected in adipocytes); any unstained cells on the adrenal slide should show background only, but HPA does not identify a validated internal negative cell type (HPA: adrenal gland row).

Positive control tissue: Adrenal gland (Glandular cells, HPA Medium)

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PRKAR1A in A-431, U-251MG, U2OS, with annotated localisation: Cytosol (approved) (HPA subcellular).

Technical controls: Include no-primary or secondary-only and rabbit IgG isotype controls matched to the primary antibody’s clonality and concentration, plus PRKAR1A knockout material as a biological negative if available (caption: rabbit anti-PRKAR1A; standard IHC practice). Check endogenous peroxidase and biotin background in adrenal sections when using the reported biotin–SABC/DAB detection method (caption: biotinylated secondary, SABC and DAB; standard IHC practice).

⚠️Feasibility: A target-specific fixation window and fixation effect are unreported, and the selected A00699-1 paraffin-section caption does not state a fixative (caption: fixative not stated). The reported IHC procedure uses heat retrieval in EDTA at pH 8.0; retrieval dependence and whether frozen sections are easier are unreported (caption: heat-mediated EDTA retrieval). IF/ICC has a separate guide; HPA reports cytosolic ICC-IF localisation, but that does not establish an easier workflow or a fixation window (HPA: Cytosol, approved).

HPA tissue IHC evidence for PRKAR1A

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — 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
Adrenal gland	Glandular cells	Medium	Protein (IHC)	HPA →
Cerebral cortex	Neuronal cells	Medium	Protein (IHC)	HPA →
Cervix	Glandular cells	Medium	Protein (IHC)	HPA →
Endometrium	Glandular cells	Medium	Protein (IHC)	HPA →
Heart muscle	Cardiomyocytes	Medium	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Adipose tissue	Adipocytes	Not detected	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	Not detected	Protein (IHC)	HPA →
Bronchus	Basal cells	Not detected	Protein (IHC)	HPA →
Epididymis	Glandular cells	Not detected	Protein (IHC)	HPA →
Esophagus	Squamous epithelial cells	Not detected	Protein (IHC)	HPA →

Section 3

Advanced PRKAR1A IHC Tips

Troubleshoot PRKAR1A staining in paraffin sections by checking retrieval, compartment, tissue controls and scoring before interpreting chromogenic signal.

What retrieval should I use when PRKAR1A staining is weak in paraffin sections?

Use heat-mediated antigen retrieval in EDTA buffer at pH 8.0 first (datasheet A00699-1). The selected antibody stained a paraffin-embedded rat testis section after this retrieval, followed by 1 μg/ml primary antibody overnight at 4°C (datasheet A00699-1). If staining remains weak, compare a second retrieval condition on serial sections while keeping antibody concentration, detection and development constant (standard IHC practice). Include a known positive section in each run, and examine morphology as well as signal: excessive heating can damage tissue or produce misleading staining (standard IHC practice).

Could fixation explain weak or patchy PRKAR1A staining?

Target-specific fixation sensitivity is unknown: the selected tissue-IHC caption identifies a paraffin-embedded section but does not state its fixative (datasheet A00699-1). Record the fixative and fixation duration for each specimen, then compare sections processed alike before attributing intensity differences to PRKAR1A expression (standard IHC practice). On serial sections, check whether tissue preservation and other stains vary across the same block; patchiness that follows processing boundaries calls for technical review (standard IHC practice). Keep retrieval at EDTA pH 8.0 during the initial comparison so fixation, retrieval and detection changes do not become confounded (datasheet A00699-1; standard IHC practice).

Where should PRKAR1A signal appear, and when is a compartment suspicious?

Expect predominantly cytoplasmic staining with possible membrane-associated signal: tissue IHC reports membranous and cytoplasmic expression, while subcellular imaging places PRKAR1A in the cytosol (HPA tissue IHC; HPA subcellular). PRKAR1A has no annotated transmembrane segment, and its interaction with AKAP19 can target it to the plasma membrane (UniProt P10644). Score cytoplasmic and membranous signal separately when both are visible, using the same criteria across specimens (standard IHC practice). Predominantly nuclear or extracellular deposits warrant review of counterstain, section edges, detection background and control sections before a biological interpretation (standard IHC practice).

Could isoforms or epitope masking account for discordant PRKAR1A staining?

PRKAR1A has 2 annotated isoforms and several modified residues, including phosphorylation sites near its amino terminus (UniProt P10644). The supplied caption gives staining conditions but no antibody epitope, so it cannot establish whether both isoforms or differently modified forms are detected (datasheet A00699-1). When samples disagree, obtain the catalog antibody’s immunogen or epitope information and check whether the recognized sequence is shared by the isoforms (standard antibody validation practice). Compare serial sections under identical EDTA pH 8.0 retrieval and detection conditions; changes caused by processing alone should not be assigned to isoform abundance (datasheet A00699-1; standard IHC practice).

How should I investigate PRKAR1A localization by multiplex IF?

Use IF as a separate validation experiment and multiplex PRKAR1A with a marker for the cell population being assessed in the tissue (standard IF practice). Cytosolic access matters because subcellular imaging places PRKAR1A in the cytosol, while tissue IHC also reports membranous signal; choose permeabilisation according to the mapped antibody epitope and assess membrane integrity alongside signal (HPA subcellular; HPA tissue IHC; standard IF practice). Select fluorophores after inspecting the specimen’s autofluorescence, and include single-stain controls to check channel bleed-through (standard IF practice). The paraffin-section retrieval and 1 μg/ml concentration belong to the selected IHC caption; establish IF conditions independently (datasheet A00699-1; standard IF practice).

How can I reduce diffuse or granular background without losing PRKAR1A signal?

Begin with the documented 10% goat-serum block and 1 μg/ml primary antibody incubated overnight at 4°C as a reference condition for this IHC-validated antibody (datasheet A00699-1). Compare a no-primary control and a positive tissue section in the same staining run; background in the former points toward detection or tissue-derived signal (standard IHC practice). For chromogenic detection, check endogenous peroxidase blocking, washing and DAB development time, adjusting one variable at a time (standard IHC practice). Keep staining away from section folds and edges when judging specificity, because concentrated reagent there can mimic a strong cellular pattern (standard IHC practice).

How should I quantify PRKAR1A when compartments and cell populations differ? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and compartment before scoring, since tissue IHC reports variable membranous and cytoplasmic PRKAR1A expression (HPA tissue IHC). For cellular staining, record the percentage of positive cells and intensity categories, then calculate an H-score with the same thresholds for every specimen (standard IHC scoring practice). For dispersed positive cells, density per mm² can be useful when the analysed tissue area is measured consistently (standard image-analysis practice). Normalise to evaluable cells or viable tissue area, exclude folds and necrosis, and compare sections stained in the same run with a shared positive control (standard IHC practice).

How do I distinguish genuine PRKAR1A staining from tissue or detection artefact?

A plausible positive follows cellular cytoplasmic or membranous boundaries, consistent with the tissue-IHC profile and approved cytosolic localization (HPA tissue IHC; HPA subcellular). Assess the expected cell population rather than treating every dark structure as equivalent: reported medium staining includes adrenal glandular cells and cortical neuronal cells, while adipocytes were not detected in the cited tissue profile (HPA tissue IHC). Signal confined to cut edges, folds or necrotic areas warrants technical review, as does staining reproduced in a no-primary control (standard IHC practice). Check endogenous enzyme activity and DAB precipitate before calling isolated dark granules PRKAR1A-positive (standard chromogenic IHC practice).

Boster reagents

Best PRKAR1A / cAMP-dependent protein kinase type I-alpha regulatory subunit IHC Antibodies

A00699-1 has paraffin-section IHC images from rat testis and human intestinal and lung cancer tissue (catalog image captions); M00699-1 lists IHC and ICC/IF for Human, Mouse and Rat, without supplied images (catalog applications/reactivity/image alts).

Real IHC data

Anti-Protein Kinase A regulatory subunit I alpha/PRKAR1A Antibody ®

Cat # A00699-1

View product →

A00699-1 will render with its rat testis IHC figure; its captions also document human intestinal and lung cancer sections (catalog image captions). M00699-1 will render as an IHC and ICC/IF-listed antibody reactive with Human, Mouse and Rat; no IHC or IF figure is supplied (catalog applications/reactivity/image alts).

Which to pick: For tissue IHC, choose A00699-1: its rat testis paraffin-section caption documents EDTA pH 8.0 retrieval, 1 μg/ml primary antibody overnight at 4°C, and DAB detection (A00699-1 image caption). The fixative is unreported (A00699-1 image caption). For IF/ICC, M00699-1 is the listed rabbit monoclonal option (catalog title/clone/applications); for cross-species work, both list Human, Mouse and Rat reactivity, while A00699-1 has image-backed IHC evidence in Human and Rat (catalog reactivity/image captions).

Each figure is that product's own IHC / IF validation image from its datasheet.

References

UniProt Consortium. UniProt entry P10644 (KAP0_HUMAN, cAMP-dependent protein kinase type I-alpha regulatory subunit).
Human Protein Atlas. PRKAR1A tissue IHC expression (reliability: Approved).
Human Protein Atlas. PRKAR1A subcellular location (ICC-IF): Localized to the cytosol..
Human Protein Atlas. PRKAR1A antibody validation summary (2 antibodies).
Epigenomic characterization and therapeutic challenges of melanoma arising in giant nevi in pediatric patients. Discover oncology 2025 — PMC12647451.
Defects of the Carney complex gene (PRKAR1A) in odontogenic tumors. Endocrine-related cancer 2015 — PMC4439291.
PRKAR1A is a functional tumor suppressor inhibiting ERK/Snail/E-cadherin pathway in lung adenocarcinoma. Scientific reports 2016 — PMC5171641.
Fibrolamellar carcinoma in the Carney complex: PRKAR1A loss instead of the classic DNAJB1-PRKACA fusion. Hepatology (Baltimore, Md.) 2018 — PMC6151295.
PubMed PMID:3426618 — UniProt-cited evidence.
PubMed PMID:2310396 — UniProt-cited evidence.
PubMed PMID:1889088 — UniProt-cited evidence.