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CEL / Bile salt-activated lipase · IHC design guide
Design Immunohistochemistry for CEL
Plan CEL chromogenic IHC in paraffin sections with pancreatic exocrine cells as a high-staining reference and lactating glandular cells as a medium-staining comparison (HPA tissue IHC). This guide covers fixation consistency and the catalog antibody’s 1:100–1:300 IHC dilution (datasheet A01821-1).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CEL 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 | CEL is secreted (UniProt); glandular cell staining is observed (HPA tissue IHC). | |
| Staining pattern | Pancreatic exocrine cells: high; lactating glands: medium; subcellular pattern unreported (HPA tissue IHC). | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A01821-1) | |
| Positive control | Pancreas+1 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 paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | Secreted CEL may stain away from its tissue RNA source (HPA tissue IHC). | |
| Regulation | Lactating glands show medium staining (HPA tissue IHC). | |
| Isoform / epitope | 2 isoforms; mature chain starts at residue 21; epitope differences unspecified (UniProt). |
Section 1
Recommended CEL IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A01821-1) is paired with a published CEL protein IHC protocol in mouse pancreas (PMC9117557).
| Sample | Paraffin-embedded human tonsil tissue; fixative not specified (datasheet A01821-1) |
| Fixation | Image fixative and duration unreported (datasheet A01821-1); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Tris-EDTA pH 9.0 (datasheet A01821-1); 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-CEL, 1:100-1:300 (datasheet A01821-1) |
| 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 | CEL-positive staining in exocrine glandular cells of pancreas (HPA tissue IHC: High). HPA tissue profile: Selective expression in exocrine glandular cells of pancreas and glandular cells in lactating breast. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated Tris-EDTA pH 9.0 for the catalog antibody (datasheet A01821-1); the published protocol used citrate pH 6.0 with a different CEL antibody (PMC9117557).
Section 2
What Is the Expected CEL Staining Pattern?
CEL is a secreted protein with no transmembrane segment (UniProt P19835 topology). In paraffin section IHC, expect the strongest staining in pancreatic exocrine glandular cells and a weaker positive pattern in lactating breast glandular cells (HPA: High in pancreas; Medium in lactating breast). HPA rates the tissue IHC profile Enhanced, while cautioning that a secreted protein’s staining location may differ from its site of RNA expression (HPA: reliability description).
| Strong staining in pancreatic exocrine glandular cells, with weaker staining in lactating breast glandular cells. | This matches the reported cell types and relative levels (HPA: High in pancreatic exocrine cells; Medium in lactating glandular cells). Assess the relevant cells rather than assigning one intensity threshold to both tissues; secretion can also separate protein location from RNA location (HPA: reliability description). |
| Predominantly nuclear staining, or a crisp cell-surface outline without a glandular secretory pattern. | Question target specificity: CEL is annotated as secreted and has no transmembrane segment (UniProt P19835 topology). Those features do not establish a precise intracellular IHC pattern; HPA provides no ICC-IF image-based location for CEL (HPA: subcellular summary). |
| Prominent staining in cell types reported as negative, such as adipocytes in adipose tissue. | HPA reports no detection in those adipocytes (HPA: adipose tissue IHC). If staining persists, consider off-target binding or endogenous detection activity as general IHC possibilities. Compare tissue morphology and appropriate staining controls before calling CEL positive. |
| Diffuse chromogen across glands, stroma, and cells without a coherent cell-type pattern. | Diffuse background cannot establish CEL localisation. The reported tissue pattern is selective for pancreatic exocrine and lactating breast glandular cells (HPA: tissue IHC profile). In general IHC practice, nonspecific reagent binding, detection chemistry, or incomplete washing can obscure a selective signal. |
| No convincing staining in pancreatic exocrine glandular cells. | Treat the run as inconclusive before interpreting another tissue as CEL negative: this is the strongest reported positive population (HPA: High in pancreatic exocrine cells). Check tissue identity and preservation, controls, antibody use, and detection performance using general IHC practice; HPA supplies no CEL-specific fixation sensitivity. |
💡Expected CEL appearanceCall positive when pancreatic exocrine glandular cells show strong staining, with medium staining possible in lactating glandular cells; dominant nuclear or unrelated-cell staining is suspect (HPA: tissue IHC; UniProt P19835 topology).
| Secreted protein and processing | CEL has a signal peptide at residues 1–20 and a mature chain at 21–753, with no transmembrane segment (UniProt P19835). Interpret cellular staining alongside possible secreted protein outside the producing cell; neither source supplies a precise IHC compartment map. |
| Tissue and cell context | Pancreatic exocrine cells are High, lactating glandular cells Medium, and several sampled cell types are Not detected (HPA: tissue IHC). HPA also notes that secreted protein and RNA locations may differ; RNA enrichment alone cannot set the stained-cell boundary. |
| Isoforms and glycosylation | UniProt lists Long and Short isoforms and 11 glycosylation sites (UniProt P19835). Antibody epitopes are not supplied here, so the record cannot predict whether either feature changes recognition or justify an antigen retrieval choice. |
| IHC validation and subcellular limits | Two listed antibodies, HPA008023 and HPA052701, have Enhanced IHC status (HPA: antibodies). HPA reports CEL as secreted but provides no ICC-IF images or main intracellular location (HPA: subcellular). These data support tissue-pattern comparison, not a fixed organelle assignment. |
| Situation | Likely cause | Next action |
|---|---|---|
| Pancreatic positive tissue is blank or faint. | A failed run is possible because exocrine glandular cells are reported High (HPA: pancreas IHC); these sources identify no CEL-specific fixation effect. | Verify the exocrine region and control slides, then review the antibody instructions and routine IHC detection steps. Record any retrieval changes as assay optimisation, not a demonstrated CEL requirement (general IHC practice). |
| Lactating breast looks weaker than pancreas. | Different strength is expected: lactating glandular cells are Medium and pancreatic exocrine cells High (HPA: tissue IHC). | Score each cell population against its own expected level and morphology. A weaker breast result alone does not indicate assay failure when the pancreatic positive control performs as expected. |
| Adipocytes or unrelated tissue cells stain strongly. | Those cells may conflict with reported negatives; adipocytes in adipose tissue are Not detected (HPA: adipose tissue IHC). Off-target binding or endogenous detection activity are general IHC possibilities. | Review cell identity, omit-primary and detection controls, and background distribution. Interpret staining as CEL only when the cell pattern is supported by the tissue evidence. |
| Chromogen coats much of the section. | Broad staining lacks the selectivity reported for CEL (HPA: tissue IHC profile). Reagent background or endogenous activity can produce diffuse colour (general IHC practice). | Inspect control slides and repeat with routine blocking, washing, and detection checks as appropriate (general IHC practice). Avoid assigning a CEL-positive cell type from diffuse colour alone. |
| Only nuclei or sharp plasma membranes stain. | A dominant nuclear or membrane outline does not follow the secreted, non-transmembrane annotation (UniProt P19835 topology); a precise intracellular reference pattern is unavailable (HPA: subcellular). | Check morphology and control staining, then compare the result with pancreatic exocrine and lactating glandular patterns (HPA: tissue IHC). Treat the unusual compartment as unresolved unless independently supported. |
| IF/ICC question: should the IHC pattern define an IF-positive cell? | No CEL ICC-IF images or main intracellular location are provided (HPA: subcellular); the listed antibodies have Enhanced IHC status but no ICC status (HPA: antibodies). | Use the separate IF/ICC guide for that application. The IHC tissue pattern can guide expectations, but it does not validate an IF compartment or substitute for IF-specific controls. |
Experiment evidence
IHC & IF images showing CEL staining
A01821-1 · IHCImmunohistochemical analysis of paraffin-embedded human tonsil. 1, Antibody was diluted at 1:200 (4° overnight). 2, Tris-EDTA, pH9.0 was use
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000170835-CEL/tissue/cerebral+cortex#imid_2394712
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000170835-CEL/tissue/colon#imid_2394638
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000170835-CEL/tissue/liver#imid_2394639
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000170835-CEL/tissue/kidney#imid_2394640
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CEL IHC & IF
🧪Run pancreas first: exocrine glandular cells should stain strongly (HPA: High in pancreas exocrine glandular cells). Use adipose tissue as the negative tissue (HPA: Not detected in adipocytes); on the pancreas slide, evaluate non-exocrine cells as candidate internal negatives, without assuming that HPA has validated them as negative.
Positive control tissue: Pancreas (Exocrine glandular 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 CEL; derive a cell-line control from the positive tissue's cell type (Exocrine glandular cells) and confirm it by RNA or western blot first.
Technical controls: Include no-primary (secondary-only) and host-species- and clonality-matched isotype controls, plus a biological negative such as CEL knockout tissue or a validated peptide-block control (standard IHC practice). Block endogenous peroxidase for chromogenic detection and assess any background in the pancreas section against these controls (standard IHC practice).
⚠️Feasibility: A target-specific fixation window and fixation effect are unreported; the selected A01821-1 paraffin-section caption does not state a fixative (selected-SKU tissue-IHC caption: fixative unreported). That caption uses Tris-EDTA retrieval at pH 9.0, but does not establish whether CEL staining depends on that retrieval condition; the supplied evidence also does not establish that frozen sections or IF are easier (selected-SKU tissue-IHC caption: Tris-EDTA pH 9.0; HPA subcellular: no ICC-IF cell-line images). Interpret luminal or extracellular staining cautiously because CEL is secreted (UniProt P19835: Secreted).
HPA tissue IHC evidence for CEL
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High consistency between antibody staining and RNA expression data. Secreted protein, tissue location of RNA and protein is expected to differ.). 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 |
|---|---|---|---|---|
| Pancreas | Exocrine glandular cells | High | Protein (IHC) | HPA → |
| Lactating breast | Lactating glandular cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced CEL IHC Tips
Troubleshoot CEL staining in paraffin sections by checking retrieval, cellular context, controls, and scoring before interpreting the signal.
What should I change when CEL staining is weak after antigen retrieval?
Begin with heat-mediated Tris-EDTA, pH 9.0, antigen retrieval for paraffin sections (datasheet A01821-1). The selected image used the catalog antibody at 1:200 overnight at 4°C, so reproduce those conditions before changing retrieval (caption A01821-1). Check a pancreas section alongside the test section, because exocrine glandular cells show high CEL staining (HPA: pancreas). If signal remains weak, compare a milder retrieval condition on adjacent sections while holding antibody dilution and detection constant (standard IHC practice). Record both staining intensity and tissue damage; stronger retrieval can make a damaged section appear deceptively positive (standard IHC practice).
Could fixation explain weak or uneven CEL staining?
Target-specific CEL sensitivity to fixation is unknown from the supplied evidence; the selected paraffin-section caption does not state a fixative (caption A01821-1). Record the actual fixative, fixation duration, specimen thickness, and time before fixation for every case, then compare sections processed together (standard IHC practice). Keep retrieval at Tris-EDTA, pH 9.0, and the primary antibody at 1:200 while assessing processing differences (datasheet A01821-1; caption A01821-1). Include a concurrently processed positive control so a weak run is distinguishable from a weak specimen (standard IHC practice). Do not assign a CEL-specific fixation effect without a direct comparison under matched staining conditions.
Where should CEL staining appear, and how should extracellular signal be read?
CEL is secreted and has no transmembrane segment, so staining need not form a membrane outline (UniProt P19835: subcellular location and topology). In tissue, expect the strongest supported cellular pattern in pancreatic exocrine glandular cells; lactating breast glandular cells have medium staining (HPA: tissue IHC). Examine glandular cytoplasm and nearby luminal material separately, since a secreted protein can appear outside its producing cell (UniProt P19835: secreted; standard IHC interpretation). Compare those compartments with the section morphology and a negative reagent control before calling diffuse extracellular color specific (standard IHC practice). Avoid treating staining of unrelated cells as evidence of CEL expression solely because adjacent secretions are positive.
Can this stain distinguish CEL isoforms or reveal an inaccessible epitope?
CEL has Long and Short isoforms, but the supplied antibody evidence does not map its epitope or establish isoform selectivity (UniProt P19835: isoforms; caption A01821-1). Therefore, report positive staining as CEL immunoreactivity rather than assigning it to one isoform. The protein contains 11 annotated glycosylation sites, which makes epitope accessibility worth investigating without assuming that glycosylation causes a staining failure (UniProt P19835: glycosylation). Compare the same antibody across adjacent sections using the documented Tris-EDTA, pH 9.0, retrieval first (datasheet A01821-1). Any isoform-specific interpretation needs independently established epitope mapping or a validated isoform-specific reagent.
How can I assess CEL by multiplex immunofluorescence?
Treat IF as a separate assay: the supplied catalog image documents paraffin-section IHC, not IF validation (caption A01821-1). Pair CEL with an independently validated marker of pancreatic exocrine glandular cells, the population with high tissue staining (HPA: pancreas). Choose spectrally separated fluorophores and inspect unstained tissue in each channel; a far-red CEL channel may help when shorter-wavelength autofluorescence is prominent (standard IF practice). CEL is secreted and lacks a transmembrane segment, so choose permeabilisation according to the antibody epitope: test it for an intracellular epitope and avoid assuming it is needed for an accessible extracellular epitope (UniProt P19835: topology; standard IF practice). Include single-stain and secondary-only controls to assess bleed-through and background (standard IF practice).
How do I reduce diffuse or granular chromogenic background?
First inspect a no-primary control alongside the CEL section to distinguish detection background from antibody-dependent color (standard IHC practice). Block endogenous peroxidase before chromogenic detection and compare development times across matched sections; these are general DAB workflow steps, not CEL-specific validation (standard IHC practice). The selected image used primary antibody at 1:200 overnight at 4°C and secondary antibody at 1:200 for 30 minutes at room temperature (caption A01821-1). If background persists, check washing, blocking, and the secondary reagent on control sections before changing retrieval (standard IHC practice). Evaluate diffuse extracellular color cautiously because CEL is secreted (UniProt P19835: subcellular location).
How should I score CEL staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the compartment and cell population before scoring: pancreatic exocrine glandular cells show high staining, whereas lactating breast glandular cells show medium staining (HPA: tissue IHC). For cellular staining, record the percentage of positive target cells and an H-score using intensity grades 0–3; apply the same thresholds to every section (standard IHC scoring practice). For extracellular staining, measure positive area or optical density per mm² of evaluable glandular tissue, separately from cellular scores (standard image analysis practice; UniProt P19835: secreted). Normalize counts to the number of evaluable target cells and area measurements to tissue area, excluding folds and necrosis (standard IHC practice). Report control performance, retrieval, and detection settings with the scores.
What separates convincing CEL staining from an IHC artefact?
A convincing result follows tissue morphology, agrees with a concurrently stained positive control, and exceeds no-primary background (standard IHC practice). Pancreatic exocrine glandular cells are a supported high-staining population, while CEL is secreted and has no transmembrane segment (HPA: pancreas; UniProt P19835: topology and subcellular location). Investigate an isolated crisp membrane outline or strong signal in an unrelated cell population before interpreting either as CEL (UniProt P19835: topology; standard IHC interpretation). Color restricted to section edges, folds, or necrotic areas suggests processing or detection artefact (standard IHC practice). Also check endogenous peroxidase with an appropriate control before attributing granular DAB color to the antibody (standard IHC practice).
Boster reagents
Best CEL / Bile salt-activated lipase IHC Antibodies
A01821-1 has IHC data from paraffin-embedded human tonsil (catalog IHC image caption). IF is listed, and Human, Mouse and Rat are listed as reactive species (catalog applications; catalog reactivity).
Real IHC data
Anti-Bile salt-activated lipase CEL Antibody
Cat # A01821-1
A01821-1 has an IHC image from paraffin-embedded human tonsil, using 1:200 primary antibody and Tris-EDTA retrieval at pH 9.0 (catalog IHC image caption). IF is listed for A01821-1, but no IF image is supplied (catalog applications; catalog IF image alts).
Which to pick: Choose A01821-1 for paraffin-section tissue IHC because its own image documents human tonsil staining; the fixative is unreported (catalog IHC image caption). For IF/ICC, A01821-1 lists IF at 1:50, but the payload supplies no IF image or ICC validation (catalog applications; catalog IF dilution; catalog IF image alts). For cross-species work, A01821-1 lists Human, Mouse and Rat reactivity; it is rabbit-hosted, and its clone is unreported (catalog reactivity; catalog host; catalog clone).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P19835 (CEL_HUMAN, Bile salt-activated lipase).
- Human Protein Atlas. CEL tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. CEL subcellular location (ICC-IF): Secreted.
- Human Protein Atlas. CEL antibody validation summary (2 antibodies).
- The sunless tanning agent dihydroxyacetone induces stress response gene expression and signaling in cultured human keratinocytes and reconstructed epidermis. Redox biology 2020 — PMC7276426.
- Low-molecular-weight chitosan scavenges methylglyoxal and N (ε)-(carboxyethyl)lysine, the major factors contributing to the pathogenesis of nephropathy. SpringerPlus 2015 — PMC4489968.
- The CEL-HYB1 Hybrid Allele Promotes Digestive Enzyme Misfolding and Pancreatitis in Mice. Cellular and molecular gastroenterology and hepatology 2022 — PMC9117557.
- Pathogenic Carboxyl Ester Lipase (CEL) Variants Interact with the Normal CEL Protein in Pancreatic Cells. Cells 2020 — PMC7017060.
- PubMed PMID:1698625 — UniProt-cited evidence.
- PubMed PMID:2265692 — UniProt-cited evidence.
- PubMed PMID:1988041 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CEL (Bile salt-activated lipase). Expected localisation CEL is secreted (UniProt); glandular cell staining is observed (HPA tissue IHC).. Antigen retrieval: Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A01821-1). Validated IHC antibody: A01821-1 at 1:100-1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Pancreas (Exocrine glandular cells); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded human tonsil tissue; fixative not specified (datasheet A01821-1); 2. Fixation: Image fixative and duration unreported (datasheet A01821-1); 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 A01821-1); 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-CEL, 1:100-1:300 (datasheet A01821-1); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Secreted CEL may stain away from its tissue RNA source (HPA tissue IHC).; Isoform / epitope: 2 isoforms; mature chain starts at residue 21 ; epitope differences unspecified (UniProt).; Regulation: Lactating glands show medium staining (HPA tissue IHC).. Evidence: UniProt P19835, HPA tissue IHC · Enhanced, HPA ICC-IF · Secreted, Datasheet A01821-1, PMC9117557. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CEL/immunohistochemistry-ihc-guide.