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SIGLEC7 / Sialic acid-binding Ig-like lectin 7 · IHC design guide
Design Immunohistochemistry for SIGLEC7
This guide helps plan paraffin SIGLEC7 IHC using immune-cell staining in bone marrow, lymph node, spleen and tonsil as reference patterns (HPA tissue IHC). It pairs those patterns with a 1:100 starting dilution for the IHC-validated antibody (datasheet: 1:100).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SIGLEC7 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 | Immune-cell cytoplasm (HPA tissue IHC); membrane (UniProt) | |
| Staining pattern | Immune cells show cytoplasmic positivity (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Bone marrow+3 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); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A06553) | |
| Caveat | Marrow/spleen peroxidase may mimic chromogenic signal (HPA tissue IHC; standard IHC practice) | |
| Regulation | Present in resting and activated NK cells (UniProt) | |
| Isoform / epitope | 4 isoforms; check whether the epitope is extracellular or cytoplasmic (UniProt) |
Section 1
Recommended SIGLEC7 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet) is accompanied by a published SIGLEC7 protocol using glioma tissue sections (PMC11357930).
| Sample | Paraffin-embedded human colon-cancer tissue; fixative not specified (datasheet A06553) |
| Fixation | Image fixative and duration unreported (datasheet A06553); 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-SIGLEC7, 1:100 (datasheet A06553) |
| 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 | SIGLEC7-positive staining in hematopoietic cells of bone marrow (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic positivity in immune cells. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 HIER at 95–98 °C for 20 min (page antigen retrieval rule); the published protocol uses Tris-EDTA pH 9.0 (PMC11357930).
Section 2
What Is the Expected SIGLEC7 Staining Pattern?
SIGLEC7 is a membrane protein with an extracellular region and a cytoplasmic tail (UniProt Q9Y286 topology). In paraffin-section IHC, expect staining in immune-cell populations, especially hematopoietic cells in bone marrow and cells in splenic red pulp; HPA describes cytoplasmic positivity in immune cells at these sites (HPA tissue IHC). HPA rates the tissue staining reliability Enhanced, while reporting medium consistency between antibody staining and RNA expression (HPA tissue IHC).
| Moderate staining in bone-marrow hematopoietic cells or splenic red-pulp cells, with other cells relatively pale (HPA tissue IHC). | This matches the reported IHC distribution and level: both populations are rated Medium, within an immune-cell profile described as cytoplasmic positivity (HPA tissue IHC). Evaluate the stained cells, rather than treating a whole positive tissue as uniformly positive (HPA tissue IHC). |
| Predominantly nuclear staining, without a convincing immune-cell pattern. | A nuclear-dominant result conflicts with the membrane topology of SIGLEC7 and HPA’s immune-cell IHC profile (UniProt Q9Y286 topology; HPA tissue IHC). Investigate staining artefact before calling it target-specific (general IHC practice). |
| Strong staining of adipocytes or appendix glandular cells. | HPA reports SIGLEC7 as Not detected in those cell populations (HPA tissue IHC). Such staining raises concern for cross-reactivity or endogenous detection activity; compare with a reagent-negative control and inspect nearby immune cells (general IHC practice). |
| Widespread, diffuse color obscures cell boundaries and tissue detail. | This cannot establish which cells express SIGLEC7 (general IHC practice). Check whether the color persists without primary antibody, and assess blocking, washes, and detection chemistry before scoring positive cells (general IHC practice). |
| No staining in bone-marrow hematopoietic cells or splenic red-pulp cells. | These are reported Medium positive populations, so a blank result warrants a technical check (HPA tissue IHC). It does not alone prove biological absence: inspect the control section and the same staining run before interpreting the specimen (general IHC practice). |
💡Expected SIGLEC7 appearanceCall an IHC result positive when identifiable immune-cell populations show moderate, cell-associated staining consistent with HPA’s cytoplasmic IHC profile; isolated strong staining of adipocytes or glandular cells is suspect, since HPA reports those sampled populations as Not detected (HPA tissue IHC).
| Cell population and sampled site | Bone-marrow hematopoietic cells, lymph-node and tonsil non-germinal-center cells, and splenic red-pulp cells are rated Medium (HPA tissue IHC). Score the reported population within each section; adjacent cells need not share its staining (HPA tissue IHC). |
| Compartment and assay | SIGLEC7 has residues 19–353 extracellular, 354–376 transmembrane, and 377–467 cytoplasmic (UniProt Q9Y286 topology). HPA describes cytoplasmic positivity in tissue IHC, while its ICC-IF summary places signal mainly at the plasma membrane and additionally in vesicles (HPA tissue IHC; HPA subcellular). |
| Antibody evidence | The reported tissue profile has Enhanced reliability, with medium staining–RNA consistency (HPA tissue IHC). CAB080396 has Enhanced IHC validation; HPA075513 has Approved ICC validation but no reported IHC status (HPA antibodies). Interpret a new antibody’s pattern against its own controls (general IHC practice). |
| Sequence features and epitope uncertainty | UniProt lists a cleaved signal peptide at residues 1–18, eight glycosylation sites, and four isoforms (UniProt Q9Y286 processing, glycosylation, isoforms). Without an antibody epitope or isoform-specific validation in these sources, those features cannot predict this assay’s staining or retrieval needs (UniProt Q9Y286; HPA antibodies). |
| Antigen retrieval | Target-specific fixation effects are not established by the supplied assay evidence. Verify with a matched IHC source before attributing a result to fixation. |
| IF/ICC Q&A: where should signal appear? | HPA places ICC-IF signal mainly at the plasma membrane, with additional vesicular signal (HPA subcellular). That approved ICC-IF localization helps interpret an IF image; it is separate from HPA’s cytoplasmic tissue-IHC description and does not specify an IF protocol (HPA subcellular; HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| The positive-control section is blank. | A missed staining step, ineffective detection, or an unsuitable assay condition is possible (general IHC practice); bone-marrow hematopoietic and splenic red-pulp cells are reported Medium positive (HPA tissue IHC). | Target-specific fixation effects are not established by the supplied assay evidence. Verify with a matched IHC source before attributing a result to fixation. |
| Only nuclei are strongly colored. | This conflicts with the membrane topology and reported immune-cell IHC profile (UniProt Q9Y286 topology; HPA tissue IHC); background or detection artefact is possible (general IHC practice). | Compare the primary-omitted section, examine counterstain and tissue detail, and require a reproducible immune-cell pattern before scoring the signal (general IHC practice; HPA tissue IHC). |
| Adipocytes or appendix glandular cells stain strongly. | Those populations are listed as Not detected (HPA tissue IHC); cross-reactivity or endogenous detection activity is possible (general IHC practice). | Check a primary-omitted control, assess endogenous activity for the detection system, and compare staining with the expected immune-cell populations (general IHC practice; HPA tissue IHC). |
| Color spreads across most of the section. | Diffuse background may follow insufficient blocking, inadequate washing, or excess detection signal (general IHC practice). It prevents a reliable comparison with HPA’s cell-specific profile (HPA tissue IHC). | Inspect the primary-omitted control; optimize blocking, washes, and detection conditions, then score only distinguishable cells (general IHC practice). |
| A positive site stains, but the expected cells are hard to identify. | HPA reports positivity in specific populations within bone marrow, lymph node, spleen, and tonsil, rather than assigning one level to every cell in those tissues (HPA tissue IHC). | Use morphology and the counterstain to locate the reported population, then record its staining separately from surrounding cells (general IHC practice; HPA tissue IHC). |
| IHC appears cytoplasmic, while an IF image shows a membrane rim. | HPA reports cytoplasmic immune-cell positivity in tissue IHC and mainly plasma-membrane localization in ICC-IF; UniProt describes a transmembrane protein (HPA tissue IHC; HPA subcellular; UniProt Q9Y286 topology). | Judge each image against its assay-specific HPA description and controls; do not reject an otherwise matching tissue-IHC result solely because its chromogenic pattern lacks a sharp membrane rim (HPA tissue IHC; HPA subcellular). |
Experiment evidence
IHC & IF images showing SIGLEC7 staining
A06553 · IHCImmunohistochemical analysis of paraffin-embedded human-colon-cancer, antibody was diluted at 1:100
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000168995-SIGLEC7/tissue/cerebral+cortex#imid_21276963
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000168995-SIGLEC7/tissue/colon#imid_21276897
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000168995-SIGLEC7/tissue/liver#imid_21276898
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000168995-SIGLEC7/tissue/kidney#imid_21276899
HPA · ICC-IF HELHuman Protein Atlas immunofluorescence, HEL, antibody HPA075513; green = SIGLEC7, blue = nucleus, red = microtubules.
HPA · ICC-IF HELHuman Protein Atlas immunofluorescence, HEL, antibody HPA075513; green = SIGLEC7, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SIGLEC7 IHC & IF
🧪Run spleen first: cells in the red pulp should stain at a Medium level (HPA: spleen, cells in red pulp). Use adipose tissue as the negative tissue, where adipocytes are Not detected (HPA: adipose tissue); on the spleen slide, unstained cells outside the stained red-pulp population provide an internal background reference, without assuming they lack SIGLEC7 (HPA: spleen, cells in red pulp).
Positive control tissue: Bone marrow (Hematopoietic cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SIGLEC7 in HEL, SiHa, THP-1, with annotated localisation: Plasma membrane (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and an isotype control matched to the primary antibody’s host species and clonality; use SIGLEC7 knockout material, if available, as a biological negative (standard IHC practice). Block endogenous peroxidase and assess background in spleen red pulp before interpreting chromogenic signal (standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A06553 paraffin-section caption gives a 1:100 dilution but does not report the fixative (selected A06553 tissue-IHC caption). Antigen-retrieval dependence and whether frozen sections or IF/ICC are easier are unreported; optimize retrieval on control sections (standard IHC practice). Spleen red pulp can contribute endogenous peroxidase background that complicates chromogenic scoring (standard IHC practice).
HPA tissue IHC evidence for SIGLEC7
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data.). 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 |
|---|---|---|---|---|
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Lymph node | Non-germinal center cells | Medium | Protein (IHC) | HPA → |
| Spleen | Cells in red pulp | Medium | Protein (IHC) | HPA → |
| Tonsil | Non-germinal center 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 → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SIGLEC7 IHC Tips
Troubleshoot SIGLEC7 staining in paraffin sections by checking retrieval, cell identity, subcellular pattern, and controls before interpreting signal intensity.
How should I retrieve SIGLEC7 in paraffin sections with weak staining?
Start with citrate buffer at pH 6.0, heated to 95–98 °C for 20 min (page retrieval rule). Allow sections to cool in the buffer, then compare the same staining run with a known positive lymphoid section (standard IHC practice; HPA: medium staining in spleen red-pulp cells). If signal remains weak, compare a second retrieval condition on adjacent sections while keeping antibody dilution and detection constant (standard IHC practice). Check that improvement appears in appropriate immune cells rather than uniformly across tissue, because the selected paraffin-section image reports a 1:100 dilution but gives no retrieval details (selected A06553 caption).
Could fixation explain weak or uneven SIGLEC7 staining?
Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative, so it cannot establish a SIGLEC7 fixation condition (selected A06553 caption). Record each block’s documented fixative and fixation time, and compare similarly processed sections before changing retrieval or antibody concentration (standard IHC practice). Examine whether patchy staining follows tissue thickness or processing boundaries, and assess a positive control processed alongside the sample (standard IHC practice). Keep those observations separate from SIGLEC7 biology: tissue staining patterns and membrane topology do not establish how fixation affects this antibody’s epitope (HPA: tissue IHC profile; UniProt Q9Y286 topology).
Should SIGLEC7 staining be membranous or cytoplasmic?
Prioritise staining associated with immune-cell outlines because SIGLEC7 is a single-pass membrane protein with an extracellular region at residues 19–353 (UniProt Q9Y286 topology). A cytoplasmic or punctate component can be plausible: tissue IHC reports cytoplasmic positivity in immune cells, while subcellular imaging reports plasma membrane and vesicles (HPA: tissue IHC profile; HPA: approved subcellular locations). Judge location within identifiable cells using the counterstain and section morphology rather than treating diffuse colour as cellular signal (standard IHC practice). If staining is exclusively nuclear or fills unrelated tissue uniformly, review controls and detection conditions before calling it SIGLEC7 (UniProt Q9Y286 topology; standard IHC practice).
How do epitope location and isoforms affect SIGLEC7 staining?
SIGLEC7 has 4 reported isoforms, so establish which sequence region the catalog antibody recognises before comparing staining across samples (UniProt Q9Y286 isoforms). Its extracellular region spans residues 19–353, the transmembrane segment 354–376, and the cytoplasmic region 377–467 (UniProt Q9Y286 topology). The extracellular region contains 8 reported glycosylation sites, making epitope accessibility a reasonable consideration, though their effect on this antibody is unknown (UniProt Q9Y286 glycosylation; standard IHC practice). If epitope mapping is unavailable, compare staining with an independently characterised antibody and the same cell-level controls; do not assign isoform-specific expression from this stain alone (standard IHC practice).
How can IF help assess ambiguous SIGLEC7 IHC staining?
On a matched section, multiplex SIGLEC7 with a validated natural-killer-cell marker and inspect whether signal belongs to the expected immune population (UniProt Q9Y286 tissue specificity; standard IF practice). Choose fluorophores after checking tissue autofluorescence in an unstained section, favouring a channel with clear separation from that background (standard IF practice). If the antibody recognises an extracellular epitope, first assess staining without permeabilisation; a cytoplasmic-tail epitope requires a permeabilisation condition validated for that antibody (UniProt Q9Y286 topology; standard IF practice). Use single-colour and secondary-only controls to distinguish bleed-through and nonspecific fluorescence from genuine colocalisation (standard IF practice).
What should I check when SIGLEC7 IHC shows widespread brown background?
Compare the test section with a no-primary control and inspect whether brown colour follows cells, tissue edges, or precipitate (standard IHC practice). Include an endogenous peroxidase block before DAB detection and check the control for residual enzyme activity (standard chromogenic IHC practice). Titrate the catalog antibody around the image-caption starting point of 1:100, changing one variable at a time (selected A06553 caption; standard IHC practice). Judge any improvement against immune-cell-rich control areas, since SIGLEC7 is predominantly expressed by natural killer cells and also occurs in granulocytes and monocytes at lower levels (UniProt Q9Y286 tissue specificity).
How should I quantify SIGLEC7-positive cells in paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the tissue compartment and count morphologically intact cells before scoring, because SIGLEC7 expression is associated chiefly with immune-cell populations (UniProt Q9Y286 tissue specificity; standard IHC practice). Report either percentage of positive cells, an intensity-weighted H-score, or positive-cell density per mm², stating the threshold and denominator (standard IHC quantification practice). For immune-cell comparisons, normalise positive counts to all evaluable immune cells in the same region; for tissue-density comparisons, use measured viable area (standard IHC quantification practice). Apply one threshold across batches, exclude folds and necrosis, and retain control-section results so changes in detection are not mistaken for biology (standard IHC practice).
When is SIGLEC7 staining convincing rather than artefactual?
A convincing result identifies discrete immune cells and a membrane-associated or vesicular pattern, allowing for the cytoplasmic positivity reported in tissue IHC (UniProt Q9Y286 tissue specificity; HPA: tissue IHC profile; HPA: approved subcellular locations). Check that the same staining run detects appropriate control cells, such as splenic red-pulp cells reported at medium intensity (HPA: spleen tissue IHC; standard IHC practice). Treat exclusive nuclear staining, uniform glandular staining, and signal confined to cut edges or necrotic areas as reasons to review specificity and section quality (UniProt Q9Y286 topology; standard IHC practice). Compare no-primary and peroxidase-block controls before interpreting brown deposits as SIGLEC7, especially where endogenous enzyme activity is suspected (standard chromogenic IHC practice).
Boster reagents
Best SIGLEC7 / Sialic acid-binding Ig-like lectin 7 IHC Antibodies
A06553 is a human-reactive anti-SIGLEC7 antibody with an IHC image from paraffin-embedded human colon cancer (catalog: reactivity; A06553 IHC image caption). IF is listed without an IF image (catalog: applications; IF image alts).
Real IHC data
Anti-CD328 SIGLEC7 Antibody
Cat # A06553
A06553 has IHC evidence from paraffin-embedded human colon cancer at 1:100 (A06553 IHC image caption). A06553 also lists IF for human samples, but supplies no IF image (catalog: applications, reactivity, IF image alts).
Which to pick: Choose A06553 for human tissue IHC because its own image shows staining of paraffin-embedded human colon cancer at 1:100; the fixative is unreported (A06553 IHC image caption). For IF, A06553 lists 1:50, but provides no IF figure or ICC validation (catalog: applications, IF dilution, IF image alts). No cross-species option is documented: A06553 lists Human reactivity only, and its clone is unreported (catalog: reactivity, clone).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9Y286 (SIGL7_HUMAN, Sialic acid-binding Ig-like lectin 7).
- Human Protein Atlas. SIGLEC7 tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. SIGLEC7 subcellular location (ICC-IF): Mainly localized to the plasma membrane. In addition localized to vesicles..
- Human Protein Atlas. SIGLEC7 antibody validation summary (2 antibodies).
- High expression of SIGLEC7 may promote M2-type macrophage polarization leading to adverse prognosis in glioma patients. Frontiers in immunology 2024 — PMC11357930.
- PubMed PMID:10567377 — UniProt-cited evidence.
- PubMed PMID:10499918 — UniProt-cited evidence.
- PubMed PMID:10764831 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SIGLEC7 (Sialic acid-binding Ig-like lectin 7). Expected localisation Immune-cell cytoplasm (HPA tissue IHC); membrane (UniProt). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A06553 at 1:100 (the product's own IHC validation image is shown). Controls (HPA): positive Bone marrow (Hematopoietic cells); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colon-cancer tissue; fixative not specified (datasheet A06553); 2. Fixation: Image fixative and duration unreported (datasheet A06553); 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-SIGLEC7, 1:100 (datasheet A06553); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A06553); Caveat: Marrow/spleen peroxidase may mimic chromogenic signal (HPA tissue IHC; standard IHC practice); Isoform / epitope: 4 isoforms; check whether the epitope is extracellular or cytoplasmic (UniProt); Regulation: Present in resting and activated NK cells (UniProt). Evidence: UniProt Q9Y286, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the plasma membrane. In addition localized to…, Datasheet A06553, PMC11357930. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SIGLEC7/immunohistochemistry-ihc-guide.