CSNK1A1 / Casein kinase I isoform alpha · IHC design guide

Design Immunohistochemistry for CSNK1A1

Plan CSNK1A1 staining in paraffin sections using the catalog antibody's IHC protocol (datasheet PB9693). Compare cell types and interpret cytoplasmic staining cautiously: the tissue profile is pending external verification and conflicts with its smooth muscle entry (HPA tissue IHC).

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

Printable CSNK1A1 IHC protocol sheet — expected localisation Cytoplasmic in the tissue profile (HPA tissue IHC), antibody PB9693, controls and protocol steps. Open the full CSNK1A1 IHC guide →

Jump to antibody recommendations → Read the full staining pattern guide ↓

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CSNK1A1 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 in the tissue profile (HPA tissue IHC)
	Staining pattern	Cytoplasmic staining in smooth muscle (HPA tissue IHC)
	Antigen retrieval	Citrate pH 6 HIER, heat-mediated (datasheet PB9693)
	Positive control ⓘ	Adrenal gland+4 more · see all
	Negative control ⓘ	Liver+3 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	Smooth muscle profile conflicts with a 'not detected' entry (HPA tissue IHC)
	Regulation	Expression regulation is unannotated (UniProt)
	Isoform / epitope	3 isoforms; check antibody epitope coverage (UniProt)

Section 1

Recommended CSNK1A1 IHC & IF Protocols

The catalog antibody uses citrate pH 6 heat retrieval (datasheet PB9693). The published melanoma and nevus IHC protocol below uses steam retrieval in DIVA buffer (PMC3131429).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded mouse intestine tissues; fixative not specified (datasheet PB9693)
Fixation	Image fixative and duration unreported (datasheet PB9693); verify before use.
Sectioning	4–5 µm sections on charged slides (standard)
Deparaffinisation	Xylene, graded ethanol series to water (standard)
Antigen retrieval	Heat retrieval: Citrate pH 6, 20 min (datasheet PB9693)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet PB9693)
Primary antibody	Rabbit anti-CSNK1A1, 0.5-1μg/ml (datasheet PB9693)
Primary incubation	Overnight at 4 °C (datasheet PB9693)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet PB9693)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	CSNK1A1-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in smooth muscle. No signal in the no-primary control.

💡Decision noteStart with citrate pH 6 heat retrieval for the catalog antibody (datasheet PB9693). Use steam retrieval in DIVA buffer when reproducing the published assay (PMC3131429).

Section 2

What Is the Expected CSNK1A1 Staining Pattern?

CSNK1A1 is primarily cytoplasmic, with reported centrosomal, spindle, kinetochore and nuclear-speckle locations (UniProt P48729: subcellular location). On paraffin sections, look for cellular staining in HPA-positive populations, including bronchial respiratory epithelium, placental trophoblasts and testicular seminiferous-duct cells (HPA: High in each). It has no transmembrane segment (UniProt P48729: topology). Treat tissue predictions cautiously: HPA rates its IHC profile Uncertain, pending external verification (HPA: reliability).

What am I looking at on my slide?
Cytoplasmic staining in bronchial respiratory epithelial cells or placental trophoblasts (HPA: High in both).	This fits the reported tissue pattern and predominant compartment (HPA: tissue IHC; UniProt P48729: cytoplasm). Judge intensity against an appropriate control on the same run; HPA’s Uncertain reliability means agreement is supportive, not independent validation (HPA: reliability; general IHC practice).
Strong, uniform nuclear staining dominates while cytoplasm is clear (UniProt P48729: cytoplasm and nuclear speckle).	Question the pattern before calling it CSNK1A1: UniProt lists nuclear speckles and mitotic structures, but those annotations do not predict uniform nuclear IHC staining (UniProt P48729: subcellular location). Compare morphology and controls, then check whether the pattern persists with an independently validated antibody (general IHC practice).
Signal appears in a population listed as Not detected, such as liver cholangiocytes (HPA: Not detected in cholangiocytes).	Review cell identification and detection controls; unexpected chromogen could reflect cross-reactivity or endogenous enzyme activity (general IHC practice). A positive call cannot be ruled out solely from the HPA example because its IHC reliability is Uncertain (HPA: reliability).
Chromogen blankets cells and extracellular areas with little cellular contrast (general IHC practice).	This is diffuse background rather than a convincing compartmental pattern (general IHC practice; UniProt P48729: subcellular location). Inspect the no-primary control and reagent background before scoring tissue cells; the broad haze does not establish CSNK1A1 expression (general IHC practice).
A chosen high-staining reference population has no discernible signal (HPA: High in adrenal glandular cells, for example).	Check that the expected cell population is present, then review retrieval, antibody dilution and detection using run controls (general IHC practice). HPA’s High designation supplies a reference expectation, not a guarantee for every specimen or antibody (HPA: High in adrenal glandular cells; HPA: reliability Uncertain).

💡Expected CSNK1A1 appearanceA persuasive positive is predominantly cytoplasmic cellular chromogen in a reported High population, such as bronchial respiratory epithelium, with clear contrast to surrounding tissue; widespread extracellular haze or dominant uniform nuclear color warrants control review (HPA: High in bronchial respiratory epithelial cells; UniProt P48729: cytoplasm and nuclear speckle; general IHC practice).

How each factor affects the staining
Compartment and cell state (UniProt P48729: subcellular location).	Cytoplasm is the broad expectation; centrosomes, spindle and kinetochore fibers are reported in specific cell-cycle contexts (UniProt P48729: subcellular location). Routine chromogenic sections may not resolve those fine structures, so do not require visible puncta to score a cellular positive (general IHC practice).
Tissue and cell selection (HPA: tissue IHC).	HPA lists High staining in adrenal glandular cells, bronchial respiratory epithelium, placental trophoblasts and testicular seminiferous-duct cells; it lists cholangiocytes as Not detected (HPA: tissue IHC). Use the named cell population when choosing comparators, with HPA’s Uncertain reliability in view (HPA: reliability).
Conflicting smooth-muscle entries (HPA: tissue IHC).	The HPA summary says cytoplasmic expression in smooth muscle, yet its smooth-muscle-cell entry says Not detected (HPA: profile; HPA: Not detected in smooth muscle cells). That conflict makes smooth muscle a poor sole positive or negative reference; document the actual cell-level observation (general IHC practice).
Antibody evidence (HPA: antibody validation).	The listed IHC antibody CAB016680 is rated Uncertain; HPA051334 is ICC Approved without an IHC rating in this payload (HPA: antibodies). An ICC rating does not establish performance on paraffin sections; interpret an unexpected IHC pattern through tissue and detection controls (general IHC practice).
Isoforms and epitope coverage (UniProt P48729: isoforms).	UniProt lists 3 isoforms and a protein-kinase domain at residues 17–285 (UniProt P48729: isoforms and domain). No antibody epitope is supplied, so this record cannot predict which isoforms the IHC reagent detects or whether retrieval exposes its epitope (general IHC practice).
IF/ICC interpretation (HPA: subcellular ICC-IF).	For the separate IF/ICC guide: HPA supports cytosolic localization and lists CACO-2, PC-3 and U2OS images, while cautioning that the localization uses antibodies targeting proteins from multiple genes (HPA: subcellular ICC-IF). Use this as a compartment comparison, not as an IHC protocol or paraffin-section validation (general IHC practice).

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
No staining in a high-reference cell population (HPA: High in bronchial respiratory epithelial cells, for example).	The sampled cells may be absent, or the run may have lost detectable signal; the HPA rating alone cannot identify why (HPA: reliability Uncertain; general IHC practice).	Confirm morphology and a positive run control; review the documented retrieval, antibody dilution and detection steps, changing one variable at a time (general IHC practice).
Strong color in the no-primary control (general IHC practice).	Background from the detection system or endogenous enzyme activity can mimic chromogenic cellular staining (general IHC practice).	Check reagent-only controls and the appropriate endogenous-activity blocking step before attributing the signal to CSNK1A1 (general IHC practice).
Diffuse chromogen obscures cell boundaries (general IHC practice).	Excess detection background or insufficient washing can prevent compartment-level interpretation (general IHC practice).	Compare the no-primary control and review blocking, washes and antibody concentration under the laboratory’s validated IHC workflow (general IHC practice).
Only uniform nuclear color is visible (UniProt P48729: subcellular location).	A dominant uniform nuclear pattern is poorly matched to the cytoplasmic expectation, although UniProt also reports nuclear speckles (UniProt P48729: cytoplasm and nuclear speckle).	Check counterstain and no-primary controls, then seek independent antibody or orthogonal evidence before assigning a nuclear CSNK1A1 pattern (general IHC practice).
A reported Not detected population stains strongly, such as liver cholangiocytes (HPA: Not detected in cholangiocytes).	Cell misidentification, cross-reactivity or endogenous detection activity are possibilities; HPA’s Uncertain profile does not prove any one of them (HPA: reliability; general IHC practice).	Verify the cell type on morphology, inspect detection controls and compare a reported High population from the same run (HPA: tissue IHC; general IHC practice).
Smooth-muscle staining disagrees with the chosen HPA reference (HPA: profile and smooth-muscle entry).	HPA reports both cytoplasmic smooth-muscle expression and a Not detected smooth-muscle-cell entry (HPA: tissue IHC).	Record the compartment and exact cells observed; use another named HPA High population and appropriate controls to assess the run (HPA: tissue IHC; general IHC practice).

Source: UniProt P48729 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing CSNK1A1 staining

IHC analysis of CSNK1A1 using anti-CSNK1A1 antibody (PB9693). CSNK1A1 was detected in paraffin-embedded section of mouse intestine tissues. Heat mediated antigen retrieval was performed in citrate buffer (pH6, epitope retrieval solution) for 20 mins. The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1μg/ml rabbit anti-CSNK1A1 Antibody (PB9693) 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.

PB9693 · IHCIHC analysis of CSNK1A1 using anti-CSNK1A1 antibody (PB9693). CSNK1A1 was detected in paraffin-embedded section of mouse intestine tissues.

IHC analysis of CSNK1A1 using anti-CSNK1A1 antibody (PB9693). CSNK1A1 was detected in paraffin-embedded section of rat intestine tissues. Heat mediated antigen retrieval was performed in citrate buffer (pH6, epitope retrieval solution) for 20 mins. The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1μg/ml rabbit anti-CSNK1A1 Antibody (PB9693) 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.

PB9693 · IHCIHC analysis of CSNK1A1 using anti-CSNK1A1 antibody (PB9693). CSNK1A1 was detected in paraffin-embedded section of rat intestine tissues. He

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000113712-CSNK1A1/tissue/cerebral+cortex#imid_5295896

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000113712-CSNK1A1/tissue/colon#imid_5295814

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000113712-CSNK1A1/tissue/liver#imid_5295823

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000113712-CSNK1A1/tissue/kidney#imid_5295816

HPA · ICC-IF CACO-2Human Protein Atlas immunofluorescence, CACO-2, antibody HPA051334; green = CSNK1A1, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for CSNK1A1 IHC & IF

🧪Start with placenta: trophoblastic cells should stain (HPA: High in trophoblastic cells). Use smooth muscle as the negative tissue (HPA: Not detected in smooth muscle cells); any unstained cells within the placenta section are only provisional internal negatives because the supplied HPA rows identify no validated negative placental cell type.

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

Negative control tissue: Liver (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show CSNK1A1 in CACO-2, PC-3, U2OS, with annotated localisation: Cytosol (supported) (HPA subcellular).

Technical controls: Run no-primary (secondary-only) and rabbit IgG isotype controls alongside CSNK1A1 knockout material, if available, as a biological specificity control (selected-SKU caption: rabbit primary; standard IHC practice). In placenta, quench endogenous peroxidase and control for endogenous biotin when using the caption’s biotinylated-secondary/SABC detection; assess autofluorescence for IF (selected-SKU caption: biotinylated secondary and SABC; standard IHC/IF practice).

⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected-SKU tissue-IHC caption does not state the fixative (selected-SKU caption: fixative unreported). The caption documents heat retrieval in citrate buffer at pH 6 for 20 minutes in a paraffin section, but does not establish that retrieval is required for every specimen (selected-SKU caption: citrate pH 6, 20 minutes). The supplied evidence does not establish whether frozen sections or IF are easier for CSNK1A1; placenta’s endogenous biotin can complicate the caption’s biotin-based detection (selected-SKU caption: biotinylated secondary and SABC; standard IHC practice).

HPA tissue IHC evidence for CSNK1A1

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — 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	High	Protein (IHC)	HPA →
Bronchus	Respiratory epithelial cells	High	Protein (IHC)	HPA →
Endometrium	Glandular cells	Medium	Protein (IHC)	HPA →
Placenta	Trophoblastic cells	High	Protein (IHC)	HPA →
Testis	Cells in seminiferous ducts	High	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Liver	Cholangiocytes	Not detected	Protein (IHC)	HPA →
Ovary	Ovarian stroma cells	Not detected	Protein (IHC)	HPA →
Seminal vesicle	Glandular cells	Not detected	Protein (IHC)	HPA →
Smooth muscle	Smooth muscle cells	Not detected	Protein (IHC)	HPA →

Section 3

Advanced CSNK1A1 IHC Tips

Troubleshoot CSNK1A1 staining in paraffin sections by checking retrieval, detection controls, cellular location, and the limits of the antibody evidence.

Which retrieval conditions should I start with for CSNK1A1 IHC?

Start with heat-mediated citrate pH 6 retrieval for 20 minutes (datasheet PB9693). This condition produced staining in a paraffin-embedded mouse intestine section with the catalog antibody at 1 µg/mL overnight at 4°C (datasheet PB9693). If staining is weak, compare a modest change in heating time or a different retrieval buffer on adjacent sections while keeping antibody concentration and detection constant (standard IHC practice). Include a no-primary control in each comparison, because stronger DAB signal alone cannot establish that newly exposed staining represents CSNK1A1 (standard IHC practice).

Could fixation explain weak or uneven CSNK1A1 staining?

The selected paraffin-section caption does not state a fixative, so target-specific CSNK1A1 sensitivity to fixation is unknown (datasheet PB9693). Record the actual fixative and fixation duration for each specimen, then compare sections processed together before attributing a signal difference to protein abundance (standard IHC practice). Examine tissue preservation and section adhesion after citrate pH 6 retrieval for 20 minutes, the condition documented for this antibody (datasheet PB9693). If a fixation variable is suspected, test matched material with the same retrieval, 1 µg/mL primary antibody, and DAB detection while changing only the preparation variable (datasheet PB9693; standard IHC practice).

How should I assess nuclear and punctate CSNK1A1 staining?

Expect a substantial cytoplasmic component: the tissue profile reports cytoplasmic expression, while the supported subcellular IF location is cytosol (HPA tissue IHC; HPA subcellular). CSNK1A1 is also annotated at centrosomes, kinetochores, nuclear speckles, basal bodies, and spindles, with centrosomal localization in interphase and kinetochore-fiber localization during mitosis (UniProt P48729). Assess puncta against cell morphology and a counterstain rather than calling every nuclear or mitotic dot positive (standard IHC practice). If a compartment-specific pattern drives the conclusion, compare it across well-preserved cells and sections, and check no-primary controls for matching deposits (standard IHC practice).

Can this stain distinguish CSNK1A1 isoforms or modified protein?

CSNK1A1 has 3 annotated isoforms and a protein kinase domain spanning residues 17–285 (UniProt P48729). The supplied product caption does not identify the antibody epitope, so a shared versus isoform-specific stain cannot be assigned from these IHC results (datasheet PB9693). Annotated modifications include phosphoserine at residues 4 and 156 and phosphothreonine at 321; the caption provides no evidence that antibody binding depends on these states (UniProt P48729; datasheet PB9693). Check epitope documentation before making an isoform or modification claim, and describe the observed chromogenic signal as CSNK1A1 immunoreactivity in the meantime (standard IHC practice).

How can IF help resolve ambiguous CSNK1A1 IHC staining?

Use IF as a separate localization check alongside chromogenic IHC: cytosol is the supported main location in the supplied subcellular profile (HPA subcellular). Multiplex CSNK1A1 with a marker for the expected cell type and compare signals within individual cells; use a nuclear counterstain to assess compartment boundaries (standard IF practice). Choose fluorophores after inspecting unstained tissue autofluorescence, and include single-label controls to assess spectral overlap (standard IF practice). CSNK1A1 has no annotated transmembrane segment, so test permeabilisation suitable for intracellular epitopes, while recognizing that the antibody epitope and IF fixation requirements are not supplied here (UniProt P48729; datasheet PB9693).

What should I check when CSNK1A1 DAB staining is diffuse?

The documented procedure used 10% goat serum blocking, 1 µg/mL primary antibody overnight at 4°C, and a biotinylated secondary for 30 minutes at 37°C (datasheet PB9693). Review the no-primary control first; persistent DAB signal there points to detection-system background rather than demonstrable CSNK1A1 binding (standard IHC practice). Peroxidase blocking, adequate washing, and checks for endogenous biotin are appropriate when troubleshooting a biotin-based DAB workflow (standard IHC practice; datasheet PB9693). If the control is clean, titrate the primary around the documented concentration and compare cellular contrast without changing retrieval or development simultaneously (standard IHC practice).

How should I quantify CSNK1A1 staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION

Choose a predefined cell population and compartment, because CSNK1A1 has cytoplasmic tissue staining and additional annotated intracellular locations (HPA tissue IHC; UniProt P48729). For chromogenic sections, report the percentage of positive eligible cells and an H-score based on staining intensity; use positive-cell density per mm² when cell counts per area answer the question (standard IHC practice). Normalize each measure to the relevant viable cell count or viable tissue area, and apply the same threshold and imaging conditions across specimens (standard IHC practice). Document whether cytoplasmic and nuclear signals were scored separately, and exclude folds, tissue edges, and necrotic regions consistently (standard IHC practice).

How do I distinguish true CSNK1A1 signal from artefact?

A plausible signal includes cytoplasmic staining, consistent with the tissue profile and supported cytosolic IF location, while selected mitotic structures may show more localized signal (HPA tissue IHC; HPA subcellular; UniProt P48729). Compare the stained cell type with the section’s anatomy: the supplied HPA examples vary by cell population, and its tissue IHC reliability is marked uncertain (HPA tissue IHC). Treat staining concentrated at cut edges, damaged or necrotic areas, or in no-primary controls as a reason to investigate processing or detection artefacts (standard IHC practice). Check endogenous enzyme background and repeat questionable patterns on well-preserved sections before interpreting them as altered CSNK1A1 localization (standard IHC practice).

Boster reagents

Best CSNK1A1 / Casein kinase I isoform alpha IHC Antibodies

PB9693 has IHC images from paraffin sections of mouse and rat intestine and human intestinal cancer (PB9693 IHC captions). No IF data are listed (PB9693 catalog).

Real IHC data

Anti-Caseine Kinase 1 alpha/CSNK1A1 Antibody ®

Cat # PB9693

View product →

PB9693 is the only card and lists IHC reactivity with human, mouse, and rat (PB9693 catalog). Its images show paraffin-section staining in mouse and rat intestine and human intestinal cancer (PB9693 IHC captions).

Which to pick: For tissue IHC, choose PB9693: its captions document citrate retrieval at pH 6 for 20 minutes, 1 μg/ml primary antibody overnight at 4°C, and DAB detection; the fixative is unreported (PB9693 IHC captions). For IF/ICC, no listed SKU has an IF/ICC application or image (PB9693 catalog). For cross-species IHC, PB9693 lists human, mouse, and rat reactivity, with paraffin-section images for all three; its clone is unspecified (PB9693 catalog; PB9693 IHC captions).

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

References

UniProt Consortium. UniProt entry P48729 (KC1A_HUMAN, Casein kinase I isoform alpha).
Human Protein Atlas. CSNK1A1 tissue IHC expression (reliability: Uncertain).
Human Protein Atlas. CSNK1A1 subcellular location (ICC-IF): Localized to the cytosol. Caution: Based on antibodies targeting proteins from multiple genes..
Human Protein Atlas. CSNK1A1 antibody validation summary (2 antibodies).
Differential expression patterns of capping protein, protein phosphatase 1, and casein kinase 1 may serve as diagnostic markers for malignant melanoma. Melanoma research 2011 — PMC3131429.
SNX24 serves as a potential prognostic biomarker and a therapeutic target in uterine corpus endometrial carcinoma according to bioinformatics and experimentations. Translational cancer research 2025 — PMC12776183.
Phosphorylation of FADD by the kinase CK1α promotes KRASG12D-induced lung cancer. Science signaling 2015 — PMC4416214.
Role of casein kinase 1A1 in the biology and targeted therapy of del(5q) MDS. Cancer cell 2014 — PMC4199102.
PubMed PMID:8050587 — UniProt-cited evidence.
PubMed PMID:7797465 — UniProt-cited evidence.
PubMed PMID:15498874 — UniProt-cited evidence.