COL7A1 / Collagen alpha-1(VII) chain · IHC design guide

Design Immunohistochemistry for COL7A1

Use the IHC-validated antibody on human paraffin sections (datasheet A01170-1). Score COL7A1 staining at squamous epithelial basal membranes (HPA tissue IHC), using consistent fixation and appropriate controls.

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

Immunohistochemistry protocol sheet for COL7A1 (IHC for COL7A1): expected localisation Squamous epithelial basal membranes (HPA tissue IHC), antibody A01170-1, validated IHC image, and IHC protocol steps — Printable **COL7A1** IHC protocol sheet — expected localisation Squamous epithelial basal membranes (HPA tissue IHC), antibody A01170-1, controls and protocol steps. Open the full COL7A1 IHC guide →

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COL7A1 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	Squamous epithelial basal membranes (HPA tissue IHC)
	Staining pattern	Basal membrane staining in squamous epithelia (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A01170-1)
	Positive control ⓘ	Placenta+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 conditions consistent across sections. (standard IHC practice; not target-specific)
	Caveat	Secreted variants may shift protein relative to tissue RNA (HPA tissue IHC)
	Regulation	No expression regulator specified (UniProt)
	Isoform / epitope	Two isoforms; epitope coverage needs checking (UniProt)

Section 1

Recommended COL7A1 IHC & IF Protocols

The catalog antibody’s IHC-P protocol (datasheet: A01170-1) is accompanied by published chromogenic IHC protocols for stomach tumors (PMC8815231) and cholangiocarcinoma tissues (PMC11415666).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human melanoma tissue; fixative not specified (datasheet A01170-1)
Fixation	Image fixative and duration unreported (datasheet A01170-1); verify before use.
Sectioning	4–5 µm sections on charged slides (standard)
Deparaffinisation	Xylene, graded ethanol series to water (standard)
Antigen retrieval	Heat retrieval: EDTA pH 8.0 (datasheet A01170-1); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A01170-1)
Primary antibody	Rabbit anti-COL7A1, 2-5μg/ml (datasheet A01170-1)
Primary incubation	Overnight at 4 °C (datasheet A01170-1)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A01170-1)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	COL7A1-positive staining in endothelial cells of placenta (HPA tissue IHC: Medium). HPA tissue profile: Expression in basal membranes of squamous epithelia. No signal in the no-primary control.

💡Decision noteStart with heat-mediated EDTA pH 8.0 retrieval for the catalog antibody (datasheet: A01170-1). The stomach-tumor protocol uses Proteinase K retrieval (PMC8815231: Methods).

Section 2

What Is the Expected COL7A1 Staining Pattern?

COL7A1 is secreted and localizes to extracellular matrix and basement membrane; it has no transmembrane segment (UniProt Q02388). In tissue IHC, expect staining along basal membranes of squamous epithelia, at the epithelial–stromal boundary rather than throughout epithelial cells (HPA tissue IHC: Enhanced; basal-membrane profile). HPA also reports medium staining in placental endothelial cells and testicular Sertoli cells (HPA tissue IHC).

What am I looking at on my slide?
A defined line follows the basal membrane beneath squamous epithelium.	This matches the reported tissue pattern and COL7A1’s extracellular basement-membrane location (HPA tissue IHC: Enhanced; UniProt Q02388). Judge the line at an intact epithelial–stromal boundary; staining across whole cells is a different pattern.
Strong nuclear or widespread cytoplasmic staining dominates the squamous epithelium.	That is discordant with the tissue IHC basal-membrane profile (HPA tissue IHC). Check the no-primary control and compare a second IHC-validated antibody where available; intracellular staining alone does not establish the expected tissue pattern (general IHC practice).
Staining appears in adipocytes or broadly in unrelated cell populations.	HPA reports adipocytes as not detected in adipose tissue, so assess such staining for cross-reactivity or endogenous detection activity (HPA tissue IHC; general IHC practice). Do not reject all cell-associated signal: placental endothelial and testicular Sertoli cells show medium staining (HPA tissue IHC).
Color covers much of the section without tracing recognizable basal membranes.	This cannot be scored as the characteristic basal-membrane pattern (HPA tissue IHC). Compare no-primary and background controls, then review blocking, antibody concentration, washing, and detection conditions as general IHC variables (general IHC practice).
No basal-membrane line is visible in a squamous epithelium chosen as a positive-pattern reference.	The result is inconclusive until tissue preservation and assay performance are checked against the HPA basal-membrane profile (HPA tissue IHC; general IHC practice). Skin-enhanced RNA supports tissue selection but does not guarantee detectable protein in every section (HPA tissue IHC).

💡Expected COL7A1 appearanceCall a positive when a clear basal-membrane line borders squamous epithelium; HPA gives no universal intensity threshold, and dominant nuclear or diffuse cellular color is discordant (HPA tissue IHC: Enhanced; UniProt Q02388).

How each factor affects the staining
Tissue compartment and validation	COL7A1 forms anchoring fibrils in stratified squamous epithelial basement membrane (UniProt Q02388). HPA calls the tissue profile Enhanced and lists two antibodies with Enhanced IHC validation, HPA042420 and CAB016357 (HPA antibodies; HPA tissue IHC).
Other reported stained cells	Medium staining is reported in placental endothelial cells and testicular Sertoli cells (HPA tissue IHC). Interpret those structures in their own tissue context; the squamous basal-membrane profile is not a rule that every positive pixel must be extracellular.
Secreted protein and precursor processing	COL7A1 has a signal peptide at residues 1–16 and a chain spanning 17–2944 (UniProt Q02388). Interpret tissue staining with its extracellular destination in mind; the record gives no antibody epitope, so it cannot predict whether precursor or processed-chain epitopes are detected.
Isoforms and modified sites	Two isoforms, five glycosylation sites, and hydroxylated residues are recorded (UniProt Q02388). Without an antibody epitope or comparative IHC data, these annotations do not establish differential staining, retrieval needs, or a tissue-specific loss of signal.
Why does ICC-IF show intracellular signal?	HPA places COL7A1 mainly in the endoplasmic reticulum, with additional vesicle localization, in ICC-IF (HPA ICC-IF). This is compatible with a secreted protein before export (UniProt Q02388); it does not replace the tissue IHC basal-membrane expectation (HPA tissue IHC).

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
The expected line is absent throughout a squamous epithelial section.	The assay may have failed, or the sampled basal membrane may be disrupted; absence alone does not establish absent COL7A1 (HPA tissue IHC; general IHC practice).	Examine the epithelial–stromal boundary and run a characterized positive-pattern section with the same staining run (HPA tissue IHC; general IHC practice).
The basal-membrane line is weak but visible.	Signal strength can depend on assay conditions; HPA’s profile specifies location, not a required numeric intensity (HPA tissue IHC; general IHC practice).	Compare sections within the same run, then optimize antibody titration and detection using controls; do not infer a COL7A1-specific fixation effect (general IHC practice).
Nuclei or entire epithelial cells stain more strongly than the boundary.	The pattern conflicts with extracellular basement-membrane localization and may reflect nonspecific detection (UniProt Q02388; HPA tissue IHC; general IHC practice).	Check no-primary and detection controls; review antibody concentration and confirm the boundary pattern with an independently IHC-validated antibody if available (HPA antibodies; general IHC practice).
Adipocytes stain prominently.	Adipocytes are reported as not detected in adipose tissue; cross-reactivity or endogenous detection activity is possible (HPA tissue IHC; general IHC practice).	Compare no-primary and endogenous-enzyme controls appropriate to the chromogen, then inspect whether any specific basal-membrane pattern remains (HPA tissue IHC; general IHC practice).
Diffuse color obscures tissue boundaries.	Background from blocking, antibody concentration, washing, or detection can prevent compartment scoring (general IHC practice).	Use background controls and adjust those general IHC conditions until basal membranes can be distinguished; score location before intensity (general IHC practice; HPA tissue IHC).
Placental endothelial or testicular Sertoli staining seems inconsistent with the main profile.	HPA separately reports medium staining in those cells while summarizing a squamous basal-membrane profile (HPA tissue IHC).	Record tissue, cell type, and compartment separately; compare with the matching HPA observation before calling the staining unexpected (HPA tissue IHC).

Source: UniProt Q02388 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing COL7A1 staining

IHC analysis of Collagen VII/COL7A1 using anti-Collagen VII/COL7A1 antibody (A01170-1). Collagen VII/COL7A1 was detected in paraffin-embedded section of human melanoma tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2μg/ml rabbit anti-Collagen VII/COL7A1 Antibody (A01170-1) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A01170-1 · IHCIHC analysis of Collagen VII/COL7A1 using anti-Collagen VII/COL7A1 antibody (A01170-1). Collagen VII/COL7A1 was detected in paraffin-embedde

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000114270-COL7A1/tissue/cerebral+cortex#imid_18309731

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000114270-COL7A1/tissue/colon#imid_18297009

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000114270-COL7A1/tissue/liver#imid_18297010

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000114270-COL7A1/tissue/kidney#imid_18397755

HPA · ICC-IF HeLaHuman Protein Atlas immunofluorescence, HeLa, antibody HPA018877; green = COL7A1, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for COL7A1 IHC & IF

🧪Run placenta first and score endothelial cells, where COL7A1 staining is Medium (HPA: placenta, endothelial cells, Medium); use adipose tissue as the negative and score adipocytes, where staining is Not detected (HPA: adipose tissue, adipocytes, Not detected). On the placenta slide, neighboring nonendothelial cells should show only background cell staining; assess extracellular basement-membrane signal separately (HPA: Medium in placental endothelial cells; UniProt Q02388: extracellular matrix and basement membrane).

Positive control tissue: Placenta (Endothelial cells, HPA Medium)

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show COL7A1 in HeLa, SiHa, U2OS, with annotated localisation: Endoplasmic reticulum (approved) (HPA subcellular).

Technical controls: Include a no-primary (secondary-only) slide, a concentration-matched rabbit IgG isotype control matched to the primary antibody’s clonality, and a COL7A1 knockout biological negative where available (selected-SKU IHC caption: rabbit primary antibody). For placental DAB staining, quench endogenous peroxidase and check for endogenous biotin background if using the caption’s streptavidin–biotin detection (selected-SKU IHC caption: SABC with DAB).

⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence, and the selected A01170-1 paraffin-section caption does not state a fixative (selected-SKU IHC caption: fixative not stated). Heat retrieval in EDTA at pH 8.0 is documented for that IHC example, but a retrieval requirement and any advantage of frozen sections or IF are unreported (selected-SKU IHC caption: EDTA heat retrieval; HPA subcellular: ICC-IF images available). In placenta, distinguish staining assigned to endothelial cells from extracellular basement-membrane staining when scoring (HPA: Medium in placental endothelial cells; UniProt Q02388: extracellular matrix and basement membrane).

HPA tissue IHC evidence for COL7A1

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. Antibody staining in cells/structures not annotated, view images.). 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
Placenta	Endothelial cells	Medium	Protein (IHC)	HPA →
Testis	Sertoli 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 COL7A1 IHC Tips

Troubleshoot COL7A1 staining by prioritizing basement membrane localisation, documented retrieval conditions, and controls matched to the specimen and detection method (UniProt Q02388; datasheet A01170-1).

Which retrieval conditions should I try first for weak COL7A1 staining?

Start with heat-mediated EDTA retrieval at pH 8.0 for paraffin sections (datasheet A01170-1). If staining is weak, optimize heating and cooling while keeping the buffer constant, then compare sections processed together (standard IHC practice). Apply the documented primary concentration of 2 μg/mL overnight at 4°C as a reference condition (datasheet A01170-1). Judge recovery at the squamous epithelial basement membrane, where COL7A1 expression is reported, rather than by stronger diffuse staining (HPA tissue IHC). Include a no-primary control to distinguish improved antigen detection from increased chromogenic background (standard IHC practice).

Could fixation explain weak staining in my paraffin sections?

Target-specific fixation sensitivity is unknown from the supplied evidence, so assess fixation as an experimental variable rather than an established COL7A1 effect. The selected image documents a paraffin section but does not state its fixative (caption A01170-1). Record fixative, fixation duration, processing history, and section age for each specimen, then compare specimens processed alike (standard IHC practice). Use the documented EDTA retrieval at pH 8.0 and 2 μg/mL primary antibody as reference conditions while evaluating processing differences (datasheet A01170-1). A reliable comparison also needs an appropriate positive tissue control on the same staining run (standard IHC practice).

Where should convincing COL7A1 staining appear in tissue?

Expect a basement membrane pattern beneath stratified squamous epithelium, consistent with COL7A1 anchoring fibrils and the reported tissue staining profile (UniProt Q02388; HPA tissue IHC). COL7A1 is secreted into extracellular matrix and has no transmembrane segment, so diffuse membrane staining around individual cells warrants scrutiny (UniProt Q02388). Examine the epithelial–stromal boundary at adequate magnification and compare intact regions with a matched negative control (standard IHC practice). An intracellular signal can reflect protein in transit, but it should not replace assessment of the tissue basement membrane pattern (UniProt Q02388; HPA subcellular). Document staining continuity and intensity separately from scattered cellular chromogen deposits (standard IHC practice).

Could epitope location or isoforms explain inconsistent staining?

COL7A1 has 2 annotated isoforms, but the supplied product evidence does not identify which isoforms its epitope detects (UniProt Q02388; datasheet A01170-1). The protein contains repeated fibronectin type-III domains and von Willebrand factor A domains, which makes epitope identity relevant when comparing antibodies (UniProt Q02388). It also has annotated glycosylation and hydroxyproline sites; their effects on this antibody’s staining are unreported (UniProt Q02388; datasheet A01170-1). Request or consult the immunogen sequence before assigning discordant staining to isoform selection or modification (standard IHC practice). Compare any second antibody by epitope and basement membrane pattern under matched processing conditions (standard IHC practice; HPA tissue IHC).

How should I investigate COL7A1 by multiplex immunofluorescence?

Use IF as a separate optimization: the documented 2 μg/mL concentration and EDTA pH 8.0 retrieval come from a chromogenic tissue IHC example (datasheet A01170-1). Multiplex with a validated squamous epithelial marker to orient the basement membrane, checking that secondary antibodies do not cross-react (HPA tissue IHC; standard IF practice). Select fluorophores after inspecting unstained tissue autofluorescence, and include single-label and no-primary controls (standard IF practice). For extracellular deposited COL7A1, begin without permeabilisation; evaluate mild permeabilisation separately if the intended readout is intracellular protein (UniProt Q02388; standard IF practice). Intracellular ER and vesicle localisation is reported in cell imaging, so score that signal separately from tissue basement membrane fluorescence (HPA subcellular; HPA tissue IHC).

How can I reduce diffuse brown staining without losing basement membrane signal?

Begin by comparing the stained section with no-primary and detection-only controls to locate nonspecific signal (standard IHC practice). The documented example used 10% goat serum blocking, a biotinylated goat anti-rabbit secondary for 30 minutes at 37°C, and DAB development (datasheet A01170-1). Check endogenous peroxidase blocking and, with a biotin-based detection system, assess endogenous biotin as possible background sources (standard IHC practice). Titrate primary antibody around the documented 2 μg/mL condition and keep wash and development conditions consistent across sections (datasheet A01170-1; standard IHC practice). Preserve a defined basement membrane pattern during optimization, since diffuse staining alone does not establish COL7A1 localisation (HPA tissue IHC).

What is the most defensible way to quantify COL7A1 IHC? ⚠ ANSWER MARKED FOR VERIFICATION

Quantify signal along an annotated epithelial basement membrane as stained length or chromogen-positive area per mm² of eligible tissue (HPA tissue IHC; standard IHC practice). Normalize stained length to total evaluable basement membrane length, excluding folds, tears, and regions lacking an intact epithelial–stromal boundary (standard IHC practice). Record intensity and continuity separately, using a consistent threshold and blinded scoring where feasible (standard IHC practice). A cell-based H-score or percent-positive-cell measure can describe cellular staining, but it does not directly measure deposited extracellular COL7A1 (UniProt Q02388; standard IHC practice). Compare specimens only after matching section preparation, retrieval, detection, and image acquisition settings (standard IHC practice).

How do I separate true COL7A1 staining from artefact?

Prioritize a continuous signal at the squamous epithelial basement membrane, consistent with extracellular anchoring fibrils and the reported tissue profile (UniProt Q02388; HPA tissue IHC). Treat isolated nuclear staining or uniform cytoplasmic staining as questionable for the tissue readout, while recognizing reported ER and vesicle localisation in cell imaging (UniProt Q02388; HPA subcellular). Inspect section edges, folds, and necrotic regions for staining that tracks damage rather than anatomy (standard IHC practice). Use a no-primary control to investigate endogenous enzyme activity or detection background, particularly when DAB deposits appear outside the expected compartment (standard IHC practice; datasheet A01170-1). Interpret discordant cellular staining cautiously because secreted protein and its source cells need not coincide (HPA tissue IHC).

Boster reagents

Best COL7A1 / Collagen alpha-1(VII) chain IHC Antibodies

A01170-1 has human tissue IHC data from paraffin sections of melanoma and tonsil (catalog image captions). No IF image data are provided (catalog payload).

Real IHC data

Anti-Collagen VII/COL7A1 Antibody ®

Cat # A01170-1

View product →

A01170-1 is listed for human IHC (catalog: applications and reactivity). Its image captions show staining of paraffin sections of human melanoma and tonsil; the fixative is unreported (catalog image captions).

Which to pick: Choose A01170-1 for human tissue IHC: it is a rabbit antibody with a listed IHC dilution of 2–5 μg/ml, and its own captions document staining in paraffin sections (catalog: host, dilution, and image captions). No IF/ICC application or image data are provided, so an IF/ICC choice cannot be validated from this payload (catalog: applications and image captions). No cross-species option is listed; A01170-1 is human-reactive only (catalog: reactivity).

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

References

UniProt Consortium. UniProt entry Q02388 (CO7A1_HUMAN, Collagen alpha-1(VII) chain).
Human Protein Atlas. COL7A1 tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. COL7A1 subcellular location (ICC-IF): Mainly localized to the endoplasmic reticulum. In addition localized to vesicles..
Human Protein Atlas. COL7A1 antibody validation summary (3 antibodies).
Therapeutic potential of recombinant human collagen XVII in blue light-induced skin photoaging: preserving epidermal-dermal structural integrity and functional homeostasis. Frontiers in bioengineering and biotechnology 2026 — PMC13161066.
Prognostic Value of Highly Expressed Type VII Collagen (COL7A1) in Patients With Gastric Cancer. Pathology oncology research : POR 2021 — PMC8426344.
Somatic mutations in collagens are associated with a distinct tumor environment and overall survival in gastric cancer. BMC cancer 2022 — PMC8815231.
The COL7A1/PI3K/AKT axis regulates the progression of cholangiocarcinoma. Heliyon 2024 — PMC11415666.
PubMed PMID:8088784 — UniProt-cited evidence.
PubMed PMID:8051117 — UniProt-cited evidence.
PubMed PMID:1307247 — UniProt-cited evidence.