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COL17A1 / Collagen alpha-1(XVII) chain · IHC design guide
Design Immunohistochemistry for COL17A1
Plan chromogenic IHC for COL17A1 using basal squamous epithelium as a staining reference (HPA tissue IHC). This guide covers the expected cellular pattern, fixation consistency and epitope considerations for shed forms (HPA tissue IHC; UniProt; standard IHC practice).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
COL17A1 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 | Basal squamous cells: cytoplasmic and membranous (HPA tissue IHC) | |
| Staining pattern | Basal squamous cells show cytoplasmic and membranous staining (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Testis+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 samples. (standard IHC practice; not target-specific) | |
| Caveat | Shed extracellular forms may alter the staining pattern (UniProt) | |
| Regulation | No expression regulator specified (UniProt) | |
| Isoform / epitope | 2 isoforms; shed forms lack the cytoplasmic region, so epitope matters (UniProt) |
Section 1
Recommended COL17A1 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by published COL17A1 IHC methods for pancreatic adenocarcinoma, renal tumors, and adamantinomatous craniopharyngioma (PMC7758145; PMC13511157; PMC12367868).
| Sample | Paraffin-embedded mouse skin tissue; fixative not specified (datasheet M03031) |
| Fixation | Image fixative and duration unreported (datasheet M03031); 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 monoclonal (clone AA-3) anti-COL17A1, 1:50 (datasheet M03031) |
| 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 | COL17A1-positive staining in elongated or late spermatids of testis (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic and membranous expression in basal layer of squamous epithelia. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 retrieval at 95–98 °C for 20 min (page protocol); the published renal and craniopharyngioma methods use higher-pH retrieval (PMC13511157; PMC12367868).
Section 2
What Is the Expected COL17A1 Staining Pattern?
COL17A1 is a hemidesmosomal transmembrane protein with a cytoplasmic N-terminus and extracellular C-terminus (UniProt Q9UMD9 topology). In paraffin-section IHC, expect membranous and cytoplasmic staining in the basal layer of squamous epithelia; HPA rates this tissue pattern Enhanced (HPA tissue IHC). Its location along the hemidesmosomal plasma membrane explains why the basal cell–basement membrane interface is a useful place to inspect (UniProt Q9UMD9 subcellular location).
| Basal cells of skin show membranous staining, with some cytoplasmic staining. | This matches the observed basal-layer pattern; HPA reports medium staining in skin basal cells and rates its tissue IHC reliability Enhanced (HPA tissue IHC). Inspect the epithelial base when judging localisation, since COL17A1 lies along the hemidesmosomal plasma membrane (UniProt Q9UMD9 subcellular location). |
| Staining is confined to nuclei or appears uniformly throughout every epithelial layer. | Treat this as a localisation mismatch requiring review: HPA describes basal-layer cytoplasmic and membranous expression, while UniProt places COL17A1 at hemidesmosomes and the basement membrane (HPA tissue IHC; UniProt Q9UMD9 subcellular location). Check the counterstain and tissue architecture before scoring it as specific (general IHC practice). |
| Strong staining appears in cells recorded as undetected, such as adrenal glandular cells. | HPA records no detected staining in those cells, so investigate antibody cross-reactivity or endogenous chromogen-generating activity (HPA tissue IHC; general IHC practice). This is a control discrepancy, not proof that every stained cell lacks COL17A1; compare the suspect section with a matched detection-only control (general IHC practice). |
| Diffuse colour covers epithelium and surrounding tissue without a readable basal pattern. | Diffuse background prevents a reliable localisation call (general IHC practice). Review blocking, antibody concentration, washes and detection-only control staining; nonspecific binding or detection background can obscure the basal pattern reported by HPA (general IHC practice; HPA tissue IHC). |
| A skin section expected to contain basal cells has no signal. | Do not score the run as a true negative until the positive control and tissue integrity are checked (general IHC practice). HPA reports medium staining in skin basal cells; absent signal warrants review of antigen retrieval, antibody dilution and chromogenic detection as general workflow checks, without assuming a COL17A1-specific fixation effect (HPA tissue IHC; general IHC practice). |
💡Expected COL17A1 appearanceA convincing positive IHC result is readable membranous with some cytoplasmic staining in basal squamous epithelial cells, with skin basal cells reported at medium intensity; diffuse colour or isolated nuclear staining is a poor match to that pattern (HPA tissue IHC; UniProt Q9UMD9 subcellular location).
| Membrane topology | COL17A1 spans the membrane at residues 468–488, with residues 1–467 cytoplasmic and 489–1497 extracellular (UniProt Q9UMD9 topology). Interpret staining with the antibody epitope in mind if that information is available; no epitope is supplied here. |
| Extracellular processing | UniProt annotates extracellular processed chains beginning at residues 524 and 531, and lists basement membrane and extracellular matrix locations (UniProt Q9UMD9 processing; subcellular location). Extracellular staining can therefore need assessment alongside the cellular basal pattern; localisation alone cannot identify which molecular form was detected. |
| Tissue and cell context | HPA reports medium staining in skin basal cells, low staining in esophageal squamous epithelial cells and high staining in late spermatids (HPA tissue IHC). Choose and interpret controls by cell type; a weaker esophageal result should not be judged against skin intensity without that context (HPA tissue IHC). |
| IHC antibody evidence | HPA043673 and HPA052963 each have Enhanced IHC validation in the supplied antibody record (HPA antibodies). That supports use of the reported tissue pattern as a reference, while the HPA tissue summary also notes presumed off-target binding that was disregarded (HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| The basal layer is faint, but the section has little diffuse background. | Low signal may reflect the tissue's reported level or an underperforming IHC run; HPA reports low esophageal and medium skin staining (HPA tissue IHC; general IHC practice). | Compare like cell types and check a skin positive control before adjusting retrieval or antibody dilution; no COL17A1-specific retrieval condition is supplied (HPA tissue IHC; general IHC practice). |
| Colour appears in a detection-only control. | The signal may arise from endogenous detection activity or reagent background rather than primary-antibody binding (general IHC practice). | Review the enzyme-blocking and detection steps, then interpret the test section only after the control is clean (general IHC practice). |
| Most cells and extracellular areas show diffuse colour. | Excess background can hide the basal membranous and cytoplasmic pattern reported by HPA (general IHC practice; HPA tissue IHC). | Review blocking, primary-antibody dilution and wash conditions against appropriate controls before assigning localisation (general IHC practice). |
| Skin basal cells are unstained, including in the positive control. | The run may have failed at retrieval, primary incubation or chromogenic detection; HPA reports medium staining in these cells (general IHC practice; HPA tissue IHC). | Check control tissue quality and each detection step, then repeat the run; do not infer target-specific fixation sensitivity from this result (general IHC practice). |
| An unexpected non-basal cell population stains strongly. | Possible explanations include cross-reactivity or endogenous detection activity; HPA's reported pattern is basal in squamous epithelia (general IHC practice; HPA tissue IHC). | Identify the cells by morphology and counterstain, compare HPA's cell-specific observations, and inspect detection-only controls before scoring (HPA tissue IHC; general IHC practice). |
| IF/ICC Q&A: Where should COL17A1 signal appear? | HPA reports the plasma membrane as the supported main location and the Golgi apparatus as an approved additional location in ICC-IF (HPA subcellular ICC-IF). | Assess membrane signal with possible Golgi signal; keep this separate from paraffin IHC scoring, and note that HPA052963 has Uncertain ICC validation in the supplied record (HPA subcellular ICC-IF; HPA antibodies). |
Experiment evidence
IHC & IF images showing COL17A1 staining
M03031 · IHCImmunohistochemical analysis of paraffin-embedded mouse skin, using Collagen XVII Antibody.
M03031 · IFImmunofluorescent analysis of A431 cells, using Collagen XVII Antibody .
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000065618-COL17A1/tissue/cerebral+cortex#imid_17600195
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000065618-COL17A1/tissue/colon#imid_17595673
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000065618-COL17A1/tissue/liver#imid_17595658
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000065618-COL17A1/tissue/kidney#imid_17595667
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA052963; green = COL17A1, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA052963; green = COL17A1, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for COL17A1 IHC & IF
🧪Run skin first and expect staining in basal-layer cells (HPA: Skin, basal-layer cells, Medium; M03031 caption: mouse-skin paraffin section). Use adipose tissue as the negative tissue, with adipocytes unstained (HPA: Adipose tissue, adipocytes, Not detected); suprabasal cells on the skin slide provide an internal negative comparison because the reported skin signal is confined to the basal layer (HPA: Skin, basal-layer cells, Medium).
Positive control tissue: Testis (Elongated or late spermatids, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show COL17A1 in A-431, U2OS, hTCEpi, with annotated localisation: Plasma membrane (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and an immunoglobulin control matched to the primary antibody’s host species, isotype and clonality; confirm specificity with knockout tissue or peptide blocking if a suitable immunogen peptide is available (standard IHC practice). Quench endogenous peroxidase and check whether skin pigment resembles the chromogen before scoring (standard IHC practice).
⚠️Feasibility: Paraffin-section IHC is documented for mouse skin, but the selected M03031 caption does not report a fixative; a target-specific fixation window or fixation effect is unreported (M03031 caption). No supplied evidence establishes a required antigen-retrieval condition or shows that frozen-section IHC or IF is easier, so optimize retrieval empirically for the IHC-validated antibody (M03031 caption; standard IHC practice). Skin pigment can complicate chromogenic scoring, so compare staining with the no-primary control (standard IHC practice).
HPA tissue IHC evidence for COL17A1
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High consistency between antibody staining and RNA expression data. At least one protein variant secreted, tissue location of RNA and protein might differ and correlation is complex. Presumed off target binding observed and disregarded.). 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 |
|---|---|---|---|---|
| Testis | Elongated or late spermatids | High | Protein (IHC) | HPA → |
| Skin | Cells in basal layer | 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 COL17A1 IHC Tips
Troubleshoot COL17A1 staining in chromogenic paraffin IHC by checking retrieval, tissue processing, basal epithelial localisation and antibody epitope coverage (UniProt Q9UMD9; HPA tissue IHC).
How should I retrieve COL17A1 when basal staining is weak?
Start with citrate pH 6.0 heat induced epitope retrieval at 95–98 °C for 20 min (page retrieval setting). Apply the same retrieval and cooling conditions to control and experimental paraffin sections, then compare staining in the basal epithelial layer rather than judging the entire section (standard IHC practice; HPA tissue IHC). If signal remains weak, check the antibody’s documented IHC conditions and test retrieval changes on adjacent sections while holding detection exposure constant (standard IHC practice). Excessive retrieval can damage tissue morphology or raise nonspecific staining, so retain the condition that preserves a readable basal boundary and low background (standard IHC practice; HPA tissue IHC).
Could fixation explain inconsistent COL17A1 staining between paraffin sections?
Target specific fixation sensitivity is unknown from the supplied evidence; the selected mouse skin IHC caption identifies paraffin embedding but does not state a fixative (caption M03031). Record the fixative, fixation duration and processing history for each specimen before comparing chromogenic signal across sections (standard IHC practice). Compare adjacent sections processed together with the same retrieval, antibody incubation and detection conditions, using intact basal epithelium as a morphological reference (standard IHC practice; HPA tissue IHC). If signal differs, assess tissue preservation and staining controls first; neither the reported localisation nor protein modifications establish a COL17A1 specific fixation effect (UniProt Q9UMD9; standard IHC practice).
Where should convincing COL17A1 staining appear in tissue IHC?
Prioritise staining at basal epithelial cells and their junction with the underlying basement membrane, consistent with hemidesmosomal COL17A1 localisation (UniProt Q9UMD9 topology; HPA tissue IHC). HPA reports cytoplasmic and membranous staining in the basal layer of squamous epithelia, so a purely linear outline is not required in every chromogenic section (HPA tissue IHC). Compare the suspected signal with the counterstained epithelial architecture and inspect whether staining follows intact basal cells across the section (standard IHC practice). Widespread nuclear staining or diffuse staining far from that compartment deserves control checks before interpretation as specific COL17A1 (UniProt Q9UMD9 topology; standard IHC practice).
How can epitope position change what COL17A1 IHC detects?
Check the antibody’s stated immunogen or epitope before comparing full length COL17A1 with processed extracellular material (UniProt Q9UMD9 processing; standard IHC practice). COL17A1 spans the membrane at residues 468–488, with residues 1–467 cytoplasmic and 489–1497 extracellular (UniProt Q9UMD9 topology). The record lists extracellular processed chains beginning at residue 524 or 531, plus 2 isoforms, so epitope coverage matters when interpreting persistent matrix staining or absent cellular staining (UniProt Q9UMD9 processing; UniProt Q9UMD9 isoforms). Without a mapped epitope, chromogenic distribution alone cannot distinguish intact protein, a processed fragment or an isoform; document that uncertainty alongside the staining pattern (UniProt Q9UMD9 processing; standard IHC practice).
How should I adapt the localisation question to multiplex IF?
On the separate IF/ICC guide, pair COL17A1 with a validated basal epithelial marker so the fluorescent signal can be assigned to the expected cell population (HPA tissue IHC; standard IF practice). Choose spectrally separated fluorophores and inspect unstained tissue autofluorescence before assigning a dim signal to the second channel (standard IF practice). Set permeabilisation according to the antibody epitope: cytoplasmic residues 1–467 need intracellular access, whereas extracellular residues 489–1497 may be accessible without it in appropriately prepared samples (UniProt Q9UMD9 topology; standard IF practice). Interpret membrane and junctional signal alongside cell boundaries; the reported plasma membrane and additional Golgi localisation comes from subcellular IF evidence (HPA subcellular).
What should I check when COL17A1 DAB staining looks diffuse?
First compare the suspected deposit with an appropriate negative control, the counterstained tissue architecture and intact basal epithelium (standard IHC practice; HPA tissue IHC). In chromogenic IHC, incomplete peroxidase blocking, excess antibody or detection reagent, and inadequate washing can produce misleading colour; optimise each variable independently (standard IHC practice). Distinguish diffuse section background from a reproducible basal cell pattern, because HPA reports cytoplasmic and membranous expression in the basal squamous layer (HPA tissue IHC). If colour accumulates at folds, torn edges or damaged tissue, review adjacent sections and processing records before calling it COL17A1 localisation (standard IHC practice).
How should I score COL17A1 staining across skin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the basal epithelial compartment before scoring, since HPA places COL17A1 staining in basal cells and UniProt places it at hemidesmosomes (HPA tissue IHC; UniProt Q9UMD9 localisation). Report the percentage of positive basal cells and staining intensity, or use an H-score calculated from those categories under a consistent scoring rule (standard IHC practice). For a linear junctional pattern, measure positive length or signal density per unit of intact epithelial basement membrane rather than per whole section area (UniProt Q9UMD9 localisation; standard IHC practice). Normalise comparisons to the number of evaluable basal cells or intact junction length, and keep retrieval, imaging and threshold settings consistent across groups (standard IHC practice).
When is an apparent COL17A1 positive result probably artefactual?
A convincing result tracks intact basal epithelial cells and their basement membrane interface, matching the reported tissue pattern and hemidesmosomal location (HPA tissue IHC; UniProt Q9UMD9 localisation). Treat dominant nuclear staining, widespread staining of unrelated cells, or colour confined to section edges as suspect until controls and adjacent sections agree (UniProt Q9UMD9 topology; standard IHC practice). Exclude necrotic or poorly preserved regions from scoring, and check whether endogenous enzyme activity explains chromogenic signal in the negative control (standard IHC practice). HPA notes presumed off target binding in its tissue assessment, so agreement with expected compartment and independent controls matters more than colour intensity alone (HPA tissue IHC).
Boster reagents
Best COL17A1 / Collagen alpha-1(XVII) chain IHC Antibodies
M03031 has IHC data from paraffin-embedded mouse skin and IF data from A431 cells (catalog image captions). Listed reactivity covers Human, Mouse, and Rat (catalog reactivity).
Real IHC data
Anti-Collagen XVII Rabbit Monoclonal Antibody
Cat # M03031
M03031 has an IHC image of paraffin-embedded mouse skin (M03031 IHC caption). M03031 also has an IF image of A431 cells and lists IHC, IF, and ICC applications (M03031 IF caption; catalog applications).
Which to pick: Choose M03031 for paraffin-section tissue IHC because its own image shows paraffin-embedded mouse skin (M03031 IHC caption); the fixative is unreported (M03031 IHC caption). For IF/ICC or work across Human, Mouse, and Rat, M03031 is the listed rabbit monoclonal clone AA-3 with IF and ICC applications and reactivity in those species (catalog host, clone, applications, and reactivity); its IF image shows A431 cells (M03031 IF caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9UMD9 (COHA1_HUMAN, Collagen alpha-1(XVII) chain).
- Human Protein Atlas. COL17A1 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. COL17A1 subcellular location (ICC-IF): Mainly localized to the plasma membrane. In addition localized to the Golgi apparatus..
- Human Protein Atlas. COL17A1 antibody validation summary (2 antibodies).
- High Expression of COL17A1 Predicts Poor Prognosis and Promotes the Tumor Progression via NF-κB Pathway in Pancreatic Adenocarcinoma. Journal of oncology 2020 — PMC7758145.
- Transcriptomic Profiling Identifies a Subset of Renal Tumors with Overlapping Features of Clear Cell Papillary Renal Cell Tumor and Renal Cell Carcinoma with Fibromyomatous Stroma. Cancers 2026 — PMC13511157.
- Whole exome sequencing study of adamantinomatous craniopharyngioma reveals the mutational characteristics of recurrent cases. Journal of neuro-oncology 2025 — PMC12367868.
- Extracellular vesicles from human urine-derived stem cells delay aging through the transfer of PLAU and TIMP1. Acta pharmaceutica Sinica. B 2024 — PMC10935484.
- PubMed PMID:1324962 — UniProt-cited evidence.
- PubMed PMID:9012408 — UniProt-cited evidence.
- PubMed PMID:15164054 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for COL17A1 (Collagen alpha-1(XVII) chain). Expected localisation Basal squamous cells: cytoplasmic and membranous (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: M03031 at 1:50 (the product's own IHC validation image is shown). Controls (HPA): positive Testis (Elongated or late spermatids); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded mouse skin tissue; fixative not specified (datasheet M03031); 2. Fixation: Image fixative and duration unreported (datasheet M03031); 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 monoclonal (clone AA-3) anti-COL17A1, 1:50 (datasheet M03031); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across samples. (standard IHC practice; not target-specific); Caveat: Shed extracellular forms may alter the staining pattern (UniProt); Isoform / epitope: 2 isoforms; shed forms lack the cytoplasmic region, so epitope matters (UniProt); Regulation: No expression regulator specified (UniProt). Evidence: UniProt Q9UMD9, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the plasma membrane. In addition localized to…, Datasheet M03031, PMC7758145, PMC13511157. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/COL17A1/immunohistochemistry-ihc-guide.