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CCK / Cholecystokinin · IHC design guide
Design Immunohistochemistry for CCK
Plan chromogenic CCK IHC on paraffin sections with a 1:50–1:200 catalog antibody dilution (datasheet: A01098). Compare staining with duodenal and small-intestinal endocrine cells and hypothalamic neuronal projections (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CCK 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 | Secreted (UniProt); hypothalamic neuronal projections (HPA tissue IHC) | |
| Staining pattern | Gut endocrine cells and hypothalamic neuronal projections (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Duodenum+2 more · see all | |
| 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 | As a secreted protein, CCK staining may differ from RNA location (HPA tissue IHC). | |
| Regulation | No specific expression regulator reported (UniProt) | |
| Isoform / epitope | No isoforms annotated; cleavage may alter epitope availability (UniProt) |
Section 1
Recommended CCK IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by one published CCK protocol using myocardial paraffin sections (PMC8405328).
| Sample | Paraffin-embedded human colorectal carcinoma tissue; fixative not specified (datasheet A01098) |
| Fixation | Image fixative and duration unreported (datasheet A01098); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat-induced epitope retrieval in citrate buffer, pH 6.0, 20 min at 95–98 °C (standard rule: cytoplasmic / membrane antigen) |
| 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-CCK, 1:50-1:200 (datasheet A01098) |
| 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 | CCK-positive staining in endocrine cells of duodenum (HPA tissue IHC: High). HPA tissue profile: Expressed in hypothalamus and neuroendocrine cells in small intestine and duodenum. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 retrieval at 95–98 °C for 20 min (page antigen retrieval); the published protocol does not specify retrieval (PMC8405328).
Section 2
What Is the Expected CCK Staining Pattern?
CCK is a secreted peptide precursor with no transmembrane segment (UniProt P06307: subcellular location and topology). In paraffin section IHC, expect staining in duodenal and small intestinal endocrine cells and hypothalamic neuronal projections (HPA tissue IHC: High). HPA rates the tissue pattern Enhanced and cautions that tissue RNA and protein locations can differ for a secreted protein (HPA tissue IHC: reliability description).
| Distinct endocrine cells stain strongly in duodenum or small intestine (HPA tissue IHC: High). | This matches HPA's observed cell type and level in both tissues (HPA tissue IHC: duodenum and small intestine). Check that staining identifies individual endocrine cells rather than a uniform epithelial sheet (general IHC practice). |
| Hypothalamic neuronal projections stain strongly (HPA tissue IHC: High). | This matches the reported neural pattern (HPA tissue IHC: hypothalamus). Low staining in cortical or hippocampal neuronal cells can also fit the atlas; compare each region with its own reported level (HPA tissue IHC: cerebral cortex and hippocampus, Low). |
| A prominent nuclear pattern appears in otherwise positive cells (HPA tissue IHC: reported cell types). | Nuclear dominance is difficult to reconcile with a secreted precursor lacking a transmembrane segment (UniProt P06307: location and topology). Review counterstain, detection background and antibody controls before interpreting it as CCK (general IHC practice). |
| Strong staining appears across an unreported cell population or in adipocytes (HPA tissue IHC: adipocytes Not detected). | The distribution conflicts with the specified HPA pattern; cross-reactivity or endogenous detection activity is possible, but appearance alone cannot distinguish them (HPA tissue IHC: observed pattern; general IHC practice). |
| Duodenal endocrine cells have no detectable signal (HPA tissue IHC: High). | A known-positive tissue failing to stain makes a negative study sample inconclusive (HPA tissue IHC: duodenum; general IHC practice). First verify tissue identity, control performance and the detection run (general IHC practice). |
💡Expected CCK appearanceCall the result positive when strong, cell-restricted staining marks duodenal or small intestinal endocrine cells or hypothalamic neuronal projections (HPA tissue IHC: High); widespread nuclear or uniform tissue staining is a suspect pattern requiring controls (UniProt P06307: Secreted; general IHC practice).
| Secretion and topology (UniProt P06307: Secreted; no transmembrane segment) | Interpret cell-associated staining alongside morphology; a secreted peptide's tissue distribution need not mirror its RNA distribution (HPA tissue IHC: reliability description). |
| Precursor processing and modifications (UniProt P06307: signal, propeptides and modified residues) | The record lists cleavage regions, glycosylation and sulfation (UniProt P06307: processing and modifications). Without an antibody epitope in this payload, it cannot establish which CCK forms the stain detects. |
| Regional and cell-type variation (HPA tissue IHC: High, Low and Not detected entries) | Use the named cells within each tissue for comparison: duodenal endocrine cells are High, while cortical neuronal cells are Low and adipocytes are Not detected (HPA tissue IHC). |
| Antibody evidence (HPA antibodies: HPA069515 Enhanced; HPA045039 Supported) | Validation differs by antibody (HPA antibodies: IHC ratings). HPA's overall Enhanced tissue reliability supports the reported pattern but does not establish every stain in a new specimen as specific (HPA tissue IHC: reliability; general IHC practice). |
| IF/ICC Q: Is a specific cellular compartment established? (HPA subcellular: main location Not available) | A: No ICC-IF image-bearing cell lines or main location are supplied (HPA subcellular). The IHC tissue pattern should not be presented as a validated IF/ICC compartment (HPA tissue IHC; HPA subcellular). |
| Situation | Likely cause | Next action |
|---|---|---|
| Positive control and study sample are both blank (HPA tissue IHC: duodenal endocrine cells High). | The run may have failed at primary antibody binding or detection (general IHC practice); these images alone do not identify which step failed. | Confirm that duodenal endocrine cells are present, then check antibody application, detection reagents and a working control slide (HPA tissue IHC: duodenum; general IHC practice). |
| Positive cells are visible, but staining is weak in duodenum (HPA tissue IHC: duodenal endocrine cells High). | Weak signal may reflect assay conditions or the particular antibody's performance (general IHC practice); HPA's High rating does not specify an optimal retrieval or dilution here (HPA tissue IHC). | Compare a known-positive section in the same run, then optimize retrieval, antibody dilution and detection using that antibody's validated IHC conditions (general IHC practice). |
| Colour covers most of the section and obscures individual cells (HPA tissue IHC: cell-restricted positive pattern). | Diffuse background may arise from detection or blocking conditions (general IHC practice); it does not resemble HPA's named positive cell populations (HPA tissue IHC). | Inspect a no-primary control, washing and blocking steps; adjust detection development so individual cells can be evaluated (general IHC practice). |
| Unexpected cells stain strongly, including adipocytes (HPA tissue IHC: adipocytes Not detected). | Cross-reactivity or endogenous detection activity may explain the discrepancy (general IHC practice); HPA tissue staining alone cannot assign the mechanism. | Run a no-primary control and compare an independently validated CCK antibody where available; judge the result against the reported cell pattern (general IHC practice; HPA antibodies: IHC ratings). |
| Predominantly nuclear staining appears in a putative positive area (UniProt P06307: Secreted). | A nuclear-dominant pattern is unexpected for the reported secreted protein (UniProt P06307: location); counterstain overlap or nonspecific detection may contribute (general IHC practice). | Review the chromogen and counterstain separately, inspect control slides and require the reported endocrine-cell or projection pattern before calling the stain CCK (general IHC practice; HPA tissue IHC). |
| A study tissue is negative while the duodenal control stains (HPA tissue IHC: duodenal endocrine cells High). | Expression varies by tissue and cell type: some listed populations are Low or Not detected (HPA tissue IHC). A working control supports the run but cannot establish expression in every study specimen (general IHC practice). | Check the exact tissue and cell population against HPA, then report absence only for the evaluated cells and assay conditions (HPA tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing CCK staining
A01098 · IHCImmunohistochemistry (IHC) analyzes of CCK (V46) pAb in paraffin-embedded human colorectal carcinoma tissue at 1:50.
HPA · HypothalamusHuman Protein Atlas IHC, Hypothalamus. Source: https://www.proteinatlas.org/ENSG00000187094-CCK/tissue/hypothalamus#imid_1126
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000187094-CCK/tissue/cerebral+cortex#imid_20519211
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000187094-CCK/tissue/colon#imid_20519129
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000187094-CCK/tissue/liver#imid_20519146
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CCK IHC & IF
🧪Run duodenum first and look for staining in its endocrine cells (HPA: High in duodenal endocrine cells). Use appendix endocrine cells as the tissue negative (HPA: Not detected in appendix endocrine cells); on the positive slide, adjacent non-endocrine cells should provide a background reference without the endocrine-cell staining pattern (HPA: High in duodenal endocrine cells).
Positive control tissue: Duodenum (Endocrine cells, 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 CCK; derive a cell-line control from the positive tissue's cell type (Endocrine cells) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host species, immunoglobulin class, and clonality (standard IHC practice). Use CCK knockout tissue if available, or a peptide-block control if the antibody’s immunizing peptide is known; check duodenal sections for endogenous peroxidase signal before chromogenic detection (standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported in the supplied evidence; the selected A01098 paraffin-section caption does not state a fixative (selected-SKU tissue-IHC caption: A01098). Retrieval dependence is also unreported, and the supplied evidence does not establish whether frozen sections or IF are easier for CCK (selected-SKU tissue-IHC caption: A01098; HPA subcellular: no ICC-IF cell-line images). In duodenum, assess signal specifically in endocrine cells and distinguish it from background in surrounding tissue (HPA: High in duodenal endocrine cells; standard IHC practice).
HPA tissue IHC evidence for CCK
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Secreted protein, tissue location of RNA and protein is expected to differ. External characterization data supports antibody staining.). 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 |
|---|---|---|---|---|
| Duodenum | Endocrine cells | High | Protein (IHC) | HPA → |
| Hypothalamus | Neuronal projections | High | Protein (IHC) | HPA → |
| Small intestine | Endocrine cells | 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 | Endocrine 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 CCK IHC Tips
Troubleshoot CCK staining by checking peptide preservation, cell type, localisation and detection controls alongside the chromogenic IHC signal.
Which retrieval conditions should I start with for paraffin section CCK IHC?
Start with citrate buffer at pH 6.0, heated to 95–98 °C for 20 minutes (page retrieval specification). Apply the same cooling and wash steps to test and control sections, then compare staining in duodenal or small intestinal endocrine cells (standard IHC practice; HPA: High in endocrine cells). If signal is weak, compare a second retrieval condition on matched sections while holding antibody concentration and detection constant (standard IHC practice). Because CCK is processed from a secreted precursor, retrieval can expose an epitope without establishing which peptide form the antibody recognizes (UniProt P06307 processing; UniProt P06307 subcellular location).
How should I assess whether fixation is causing weak CCK staining?
The selected CCK image shows paraffin embedded human colorectal carcinoma at 1:50, but its caption does not state a fixative (A01098 caption). Target specific fixation sensitivity is therefore unknown; do not infer it from the tissue staining profile or CCK processing annotations (A01098 caption; HPA tissue IHC; UniProt P06307 processing). Record fixative, fixation duration and block age for each specimen, and compare sections processed together before changing retrieval or antibody concentration (standard IHC practice). Use a known staining control and a no primary control in the same run to distinguish specimen dependent signal loss from detection background (standard IHC practice).
Where should convincing CCK staining appear in tissue sections?
Prioritize staining in duodenal and small intestinal endocrine cells, with hypothalamic neuronal projections as another reported positive pattern (HPA: High in those cells and projections). CCK is secreted and has no transmembrane segment, so a crisp, continuous cell surface outline should prompt a specificity check (UniProt P06307 subcellular location and topology). Evaluate chromogenic signal against cell morphology and the counterstain, then compare its distribution with a no primary section (standard IHC practice). Extracellular signal alone cannot identify its producing cell, because tissue RNA and protein locations can differ for this secreted protein (HPA: reliability description; UniProt P06307 subcellular location).
Could peptide processing explain inconsistent CCK staining between specimens?
CCK has 0 annotated isoforms in the supplied record, but its 115 amino acid precursor undergoes signal peptide and propeptide processing (UniProt P06307 isoforms and processing). The record also lists glycosylation at residue 31, sulfotyrosines and an amidated phenylalanine, so epitope accessibility may depend on which processed form is present (UniProt P06307 glycosylation and modified residues). Check the catalog antibody’s stated immunogen or epitope before comparing scores across compartments or specimen preparation methods (standard IHC practice). If that information is unavailable, report staining as CCK immunoreactivity rather than assigning it to a particular mature peptide (UniProt P06307 processing; standard IHC practice).
How can I check CCK signal in a multiplex IF experiment?
Pair CCK with a validated marker of the expected endocrine cell population in intestinal sections, or an appropriate neuronal marker when examining hypothalamic projections (HPA: High in intestinal endocrine cells and hypothalamic neuronal projections; standard IF practice). Choose fluorophores after inspecting unstained tissue autofluorescence, and include single stain controls to assess bleed through (standard IF practice). CCK is secreted and lacks a transmembrane segment; choose permeabilisation according to whether the antibody’s epitope is intracellular or accessible without permeabilisation (UniProt P06307 subcellular location and topology; standard IF practice). Establish IF fixation and permeabilisation empirically, since the supplied paraffin image reports neither IF performance nor fixation conditions (A01098 caption; standard IF practice).
What should I check when the chromogenic signal is diffuse or widespread?
Compare the test section with a no primary control and an appropriate negative tissue section; HPA reports adipocytes in adipose tissue as not detected (standard IHC practice; HPA: adipose tissue adipocytes). Check whether peroxidase blocking suppresses signal unrelated to primary antibody binding, and assess DAB development time on matched sections (standard chromogenic IHC practice). Widespread colour in morphologically unrelated cells warrants review of blocking, antibody concentration and wash conditions before interpretation (standard IHC practice). The selected paraffin carcinoma image used 1:50, but that image alone does not establish an optimal dilution for other specimens (A01098 caption).
How should I score CCK staining across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and region before scoring: intestinal endocrine cells and hypothalamic neuronal projections represent distinct reported staining patterns (HPA: High in those cells and projections; standard IHC practice). For endocrine cells, report the percentage positive and an intensity based H-score, normalizing counts to all evaluable cells of the defined population (standard IHC quantification practice). For projection rich regions, measure positive signal density per mm² of viable annotated tissue rather than counting profiles as cells (standard IHC quantification practice). Keep section thickness, retrieval, detection and colour threshold consistent, and exclude folds and necrotic areas from the denominator (standard IHC quantification practice).
How do I distinguish specific CCK staining from an artefact?
Look for signal in expected endocrine cells or hypothalamic neuronal projections, then compare its intensity and distribution with matched controls (HPA: High in those cells and projections; standard IHC practice). A continuous membrane rim is unexpected for a secreted protein without a transmembrane segment and merits antibody specificity review (UniProt P06307 subcellular location and topology). Treat staining confined to section edges or necrotic areas cautiously, and check the no primary section for endogenous enzyme signal (standard chromogenic IHC practice). Because secreted protein can appear away from its source, extracellular colour by itself is insufficient to assign a CCK producing cell (HPA: reliability description; UniProt P06307 subcellular location).
Boster reagents
Best CCK / Cholecystokinin IHC Antibodies
A01098 has real IHC data from a paraffin-embedded human colorectal carcinoma section (IHC image caption). Human, mouse and rat reactivity is listed; IF data is absent (catalog applications and images).
Real IHC data
Anti-CCK (V46) Antibody
Cat # A01098
A01098 is the only SKU shown and is listed for IHC (catalog applications). Its image shows CCK staining in paraffin-embedded human colorectal carcinoma tissue at 1:50 (IHC image caption).
Which to pick: Choose A01098 for paraffin-section tissue IHC; its own image documents that sample and dilution, but does not report the fixative (IHC image caption). No listed SKU supports an IF/ICC choice (catalog applications and images). A01098 lists human, mouse and rat reactivity and is described as a polyclonal antibody, although its IHC image documents only human tissue (catalog reactivity; IHC image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P06307 (CCKN_HUMAN, Cholecystokinin).
- Human Protein Atlas. CCK tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. CCK subcellular location (ICC-IF): Secreted.
- Human Protein Atlas. CCK antibody validation summary (2 antibodies).
- Localization of Cholecystokinin/Sulfakinin Neuropeptides in Biomphalaria glabrata, an Intermediate Host for Schistosomiasis. The Journal of comparative neurology 2025 — PMC11841659.
- The dorsomedial hypothalamus mediates stress-induced hyperalgesia and is the source of the pronociceptive peptide cholecystokinin in the rostral ventromedial medulla. Neuroscience 2013 — PMC3638803.
- Cholecystokinin Expression in the Development of Myocardial Hypertrophy. Scanning 2021 — PMC8405328.
- Cholecystokinin in white sea bream: molecular cloning, regional expression, and immunohistochemical localization in the gut after feeding and fasting. PloS one 2012 — PMC3527491.
- PubMed PMID:3856870 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
- PubMed PMID:9371719 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CCK (Cholecystokinin). Expected localisation Secreted (UniProt); hypothalamic neuronal projections (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A01098 at 1:50-1:200 (the product's own IHC validation image is shown). Controls (HPA): positive Duodenum (Endocrine cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colorectal carcinoma tissue; fixative not specified (datasheet A01098); 2. Fixation: Image fixative and duration unreported (datasheet A01098); 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-induced epitope retrieval in citrate buffer, pH 6.0 , 20 min at 95–98 °C…; 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-CCK, 1:50-1:200 (datasheet A01098); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: As a secreted protein, CCK staining may differ from RNA location (HPA tissue IHC).; Isoform / epitope: No isoforms annotated; cleavage may alter epitope availability (UniProt); Regulation: No specific expression regulator reported (UniProt). Evidence: UniProt P06307, HPA tissue IHC · Enhanced, HPA ICC-IF · Secreted, Datasheet A01098, PMC8405328. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CCK/immunohistochemistry-ihc-guide.