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PDZD2 / PDZ domain-containing protein 2 · IHC design guide
Design Immunohistochemistry for PDZD2
Plan PDZD2 paraffin-section IHC around mainly cytoplasmic staining in connective tissue (HPA tissue IHC). Tonsil squamous epithelial cells show medium staining, but tissue results need cautious interpretation because antibody staining has low concordance with RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
PDZD2 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 | Mainly cytoplasmic staining in connective tissue (HPA tissue IHC) | |
| Staining pattern | Connective tissue: mainly cytoplasmic staining (HPA tissue IHC) | |
| Antigen retrieval | Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen) | |
| Positive control | Tonsil | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections (standard IHC practice; not target-specific) | |
| Caveat | Antibody staining has low concordance with RNA expression (HPA tissue IHC) | |
| Regulation | No specific induction cue annotated (UniProt) | |
| Isoform / epitope | 2 isoforms; processed chain spans 2493–2839. Check epitope location (UniProt) |
Section 1
Recommended PDZD2 IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol with a published PDZD2 tumor-tissue IHC procedure (PMC6448123).
| Sample | Paraffin-embedded human heart tissue; fixative not specified (datasheet A10309-1) |
| Fixation | Image fixative and duration unreported (datasheet A10309-1); 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 Tris-EDTA buffer, pH 9.0, 20 min at 95–98 °C (standard rule: nuclear 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-PDZD2, 1:100 - 1:300 (datasheet A10309-1) |
| 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 | PDZD2-positive staining in squamous epithelial cells of tonsil (HPA tissue IHC: Medium). HPA tissue profile: Mainly expressed in connective tissue and cytoplasm. No signal in the no-primary control. |
💡Decision noteTry Tris-EDTA pH 9.0 at 95–98 °C for 20 min first (page retrieval setting); the published study does not specify its antigen-unmasking conditions (PMC6448123).
Section 2
What Is the Expected PDZD2 Staining Pattern?
PDZD2 is reported in cytoplasm and connective tissue by tissue IHC, with medium staining in tonsil squamous epithelial cells (HPA tissue IHC). Plasma membrane and cytosol localisation is supported by ICC-IF; UniProt also lists nucleus, endoplasmic reticulum and secretion, with no transmembrane segment (HPA subcellular; UniProt O15018 topology). Treat the tissue pattern as provisional: HPA rates its IHC reliability Uncertain because antibody staining and RNA expression have low consistency (HPA tissue IHC).
| Medium chromogenic signal in tonsil squamous epithelial cells, chiefly cytoplasmic, with cell boundaries sometimes apparent (HPA tissue IHC; HPA subcellular). | This fits the reported tonsil level and cytoplasmic tissue pattern (HPA tissue IHC). Boundary staining is plausible given supported plasma membrane localisation in ICC-IF, but that evidence does not establish an IHC membrane pattern (HPA subcellular). Score the named cells and compartments separately (standard IHC practice). |
| Strong staining confined to an unexpected compartment, without the reported cytoplasmic pattern (HPA tissue IHC). | Consider artefact or off-target staining and inspect morphology and controls (standard IHC practice). Nuclear or endoplasmic reticulum signal alone cannot rule out PDZD2 because UniProt lists both locations; HPA tissue IHC reliability is Uncertain (UniProt O15018; HPA tissue IHC). |
| Prominent signal in adipocytes or appendix glandular cells, or broadly across unrelated cell types (HPA tissue IHC). | HPA reports those named cells as Not detected, so the result warrants review (HPA tissue IHC). Cross-reactivity or endogenous chromogenic activity are possible explanations, especially if signal also appears in a no-primary control (standard IHC practice). |
| Diffuse colour across tissue, stroma and blank areas obscures cell boundaries (standard IHC practice). | This does not support a cell-specific localisation call (standard IHC practice). Examine the no-primary control and detection chemistry, then optimise blocking, washing or primary concentration as indicated by the control result (standard IHC practice). |
| No signal in tonsil squamous epithelial cells reported as Medium by HPA (HPA tissue IHC). | Check tissue identity, morphology, retrieval conditions, antibody dilution and detection controls before interpreting a negative result (standard IHC practice). The HPA positive is provisional because its tissue IHC reliability is Uncertain; absence alone cannot establish biological loss (HPA tissue IHC). |
💡Expected PDZD2 appearanceA plausible positive is Medium, chiefly cytoplasmic chromogenic staining in tonsil squamous epithelial cells; widespread colour in HPA Not detected cells or blank areas suggests a false positive, subject to HPA's Uncertain IHC reliability (HPA tissue IHC; standard IHC practice).
| IHC evidence strength (HPA tissue IHC; HPA antibodies). | The tissue profile is Uncertain, and each listed antibody with an IHC rating is Uncertain (HPA tissue IHC; HPA antibodies). Use the reported pattern as a comparison point, not an independently verified specificity standard (HPA tissue IHC). |
| Compartment and topology (HPA subcellular; UniProt O15018 topology). | ICC-IF supports plasma membrane and cytosol localisation, while UniProt also lists nucleus, endoplasmic reticulum and secretion (HPA subcellular; UniProt O15018). With no transmembrane segment annotated, membrane staining should not be interpreted as evidence that PDZD2 spans the membrane (UniProt O15018 topology). |
| Isoforms and tissue context (UniProt O15018; HPA tissue IHC). | UniProt records 2 isoforms and reports isoform 2 protein in prostate and many prostate tumors (UniProt O15018). That does not supply an IHC intensity or distinguish isoforms in a stained section; interpret the tonsil observation within HPA's Uncertain tissue profile (HPA tissue IHC). |
| Processing and epitope position (UniProt O15018). | UniProt lists a full-length chain at residues 1–2839 and a processed chain at 2493–2839 (UniProt O15018). Without an antibody epitope in the supplied evidence, neither chain's detection nor an effect of processing on staining can be predicted. |
| Antigen retrieval (standard IHC practice). | Document retrieval conditions and compare control sections when optimising paraffin IHC (standard IHC practice). The supplied HPA and UniProt records report no PDZD2-specific retrieval or fixation sensitivity; a changed signal cannot be assigned to PDZD2 epitope masking from these sources. |
| What does IF/ICC add? (HPA subcellular). | HPA supports plasma membrane and cytosol localisation in ICC-IF and lists images from HeLa, PC-3, U2OS, EFO-21, SiHa and NIH 3T3 (HPA subcellular). That is a localisation cross-check; this section makes no IF/ICC protocol recommendation. |
| Situation | Likely cause | Next action |
|---|---|---|
| Tonsil squamous epithelium is blank despite the reported Medium stain (HPA tissue IHC). | Tissue selection, retrieval, dilution or detection may be responsible; HPA's positive profile is itself Uncertain (standard IHC practice; HPA tissue IHC). | Confirm the cell type and section quality, then check the run's detection control and recorded retrieval and primary conditions before revising the biological interpretation (standard IHC practice). |
| Adipocytes or appendix glandular cells stain strongly although HPA reports Not detected (HPA tissue IHC). | Off-target binding or endogenous chromogenic activity is possible; HPA's negative observations are not definitive specificity tests (standard IHC practice; HPA tissue IHC). | Inspect a no-primary control and compare signal placement with the tissue morphology and the tonsil reference cells; report the discrepancy rather than calling it confirmed PDZD2 expression (standard IHC practice; HPA tissue IHC). |
| Colour is diffuse or appears in blank regions of the slide (standard IHC practice). | Background from detection chemistry, insufficient blocking or washing, or excessive primary concentration can obscure a cell-specific pattern (standard IHC practice). | Use a no-primary control to locate the background source, then adjust blocking, washes or primary concentration one condition at a time; rescore only interpretable cells (standard IHC practice). |
| Signal appears only in nuclei or another compartment, with little cytoplasmic staining (HPA tissue IHC). | This departs from HPA's chiefly cytoplasmic tissue description, although UniProt includes nuclear localisation; compartment alone cannot settle identity (HPA tissue IHC; UniProt O15018). | Check counterstain, cellular boundaries and controls, and record nuclear and cytoplasmic scores separately; treat the result as unresolved if the controls do not explain it (standard IHC practice). |
| Connective tissue staining makes epithelial scoring difficult (HPA tissue IHC). | HPA describes connective tissue expression as part of its tissue profile, so stromal colour can complicate assignment to nearby squamous epithelial cells (HPA tissue IHC). | Use morphology and the counterstain to mark epithelial and connective tissue regions, then score each separately; avoid assigning stromal colour to epithelial cells (standard IHC practice). |
| Two antibodies yield different tissue patterns (HPA antibodies). | HPA assigns Uncertain IHC status to every listed antibody with an IHC rating, and the tissue profile has low staining-to-RNA consistency (HPA antibodies; HPA tissue IHC). | Compare the same cell types, compartments and controls across sections, document the disagreement, and avoid treating agreement with one antibody as proof of specificity (standard IHC practice; HPA antibodies). |
Experiment evidence
IHC & IF images showing PDZD2 staining
A10309-1 · IHCImmunohistochemistry analysis of paraffin-embedded human heart tissue, using PDZD2 Antibody. The picture on the right is blocked with the sy
A10309-1 · IFImmunofluorescence analysis of HepG2 cells, using PDZD2 Antibody. The picture on the right is blocked with the synthesized peptide.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000133401-PDZD2/tissue/cerebral+cortex#imid_17944407
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000133401-PDZD2/tissue/colon#imid_17944317
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000133401-PDZD2/tissue/liver#imid_17944318
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000133401-PDZD2/tissue/kidney#imid_17944319
HPA · ICC-IF HeLaHuman Protein Atlas immunofluorescence, HeLa, antibody HPA036504; green = PDZD2, blue = nucleus, red = microtubules.
HPA · ICC-IF HeLaHuman Protein Atlas immunofluorescence, HeLa, antibody HPA036504; green = PDZD2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for PDZD2 IHC & IF
🧪Run tonsil first: its squamous epithelial cells should show PDZD2 staining (HPA: Medium in tonsil squamous epithelial cells). Use adipose tissue adipocytes as the negative comparator (HPA: Not detected in adipocytes); other cells on the tonsil slide should be assessed for background staining without assuming they are PDZD2-negative.
Positive control tissue: Tonsil (Squamous epithelial cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PDZD2 in HeLa, PC-3, U2OS, EFO-21, SiHa, NIH 3T3, with annotated localisation: Plasma membrane (supported), Cytosol (supported) (HPA subcellular).
Technical controls: Include no-primary (secondary-only) and host-species-, class-, and clonality-matched isotype controls, plus PDZD2 knockout material or cognate-peptide competition if available (standard IHC practice; A10309-1 caption: peptide-blocked heart section). Check endogenous peroxidase in tonsil for chromogenic detection, and endogenous biotin if detection uses biotin (standard IHC practice).
⚠️Feasibility: A target-specific fixation window and the effect of fixation are unreported; the selected A10309-1 paraffin-section caption does not state a fixative. Retrieval dependency is unreported, so optimize antigen retrieval empirically (standard IHC practice). HPA has ICC-IF images for PDZD2 in HeLa, PC-3, U2OS, EFO-21, SiHa, and NIH 3T3, but the supplied evidence does not establish whether frozen sections or IF are easier than paraffin IHC, or identify a tonsil-specific artefact (HPA: subcellular ICC-IF image list).
HPA tissue IHC evidence for PDZD2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — Low consistency between antibody staining and RNA expression data. Pending external verification.). 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 |
|---|---|---|---|---|
| Tonsil | Squamous epithelial cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | 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 → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced PDZD2 IHC Tips
Troubleshoot PDZD2 staining by keeping retrieval, detection, and scoring consistent while checking cellular location and the limits of the available tissue evidence.
Which retrieval condition should I try first for PDZD2 in paraffin sections?
Start PDZD2 paraffin IHC with Tris-EDTA, pH 9.0, HIER at 95–98 °C for 20 min (page retrieval rule: nuclear antigen). If signal is weak, adjust retrieval time on adjacent sections while keeping antibody incubation and chromogen development constant (general IHC practice). If that condition damages tissue or gives excessive background, compare citrate at pH 6.0 as a fallback (general IHC practice). Score comparable cells and compartments because PDZD2 has reported nuclear, cytoplasmic, and endoplasmic reticulum locations (UniProt O15018). The selected peptide-blocked heart image supports a competition control, but its caption supplies no retrieval condition (selected A10309-1 caption).
How should I assess whether fixation is masking PDZD2?
Target-specific fixation sensitivity is unknown from the supplied evidence; the selected heart caption says paraffin embedded but does not identify a fixative (selected A10309-1 caption). For a controlled pilot, compare matched, thin specimens fixed for 6 h and 24 h in 10% neutral buffered formalin, with processing and section thickness held constant (general IHC practice). Apply the same Tris-EDTA pH 9.0 retrieval to both groups (page retrieval rule: nuclear antigen). Record signal, background, morphology, and the scored cell population before changing retrieval or antibody concentration (general IHC practice). Do not treat any difference as established PDZD2 fixation sensitivity until it is reproduced on matched material.
Which staining compartments are plausible for PDZD2?
Evaluate nuclear, cytoplasmic, and endoplasmic reticulum staining as plausible patterns (UniProt O15018), while recording membrane and cytosolic staining separately (HPA subcellular). HPA reports supported plasma membrane and cytosol localisation, whereas UniProt also reports secretion and cell-cell contacts in lung epithelial cells (HPA subcellular; UniProt O15018). PDZD2 has no annotated transmembrane segment, so a crisp membrane rim alone does not establish an integral membrane pool (UniProt O15018 topology). Examine matched cells at 20× and 40× before assigning compartment scores (general IHC practice). Compare the pattern with peptide competition where available; the selected heart caption describes a peptide-blocked image (selected A10309-1 caption).
Can this stain distinguish full-length PDZD2 from its processed form or isoforms?
Do not assign an isoform or processed product from staining alone: the supplied evidence identifies 2 isoforms but does not map this antibody’s epitope (UniProt O15018; selected A10309-1 caption). The annotated processed chain spans residues 2493–2839, including the last 2 PDZ domains (UniProt O15018). Ask whether the immunogen lies inside that interval before interpreting staining as recognition of the processed chain (general IHC practice). Isoform 2 has protein-level expression reported in prostate and many prostate tumors, which does not establish isoform identity in another specimen (UniProt O15018). Peptide competition tests competition by the supplied peptide, not discrimination between isoforms (selected A10309-1 caption; general IHC practice).
How can I extend this PDZD2 study to multiplex IF?
Treat IF with this catalog antibody as an assay requiring its own validation; the supplied selected-SKU image documents paraffin IHC and peptide competition (selected A10309-1 caption). Pair PDZD2 with a validated marker for the expected cell population, such as squamous epithelial cells in tonsil, where HPA reports medium staining (HPA tissue IHC). Choose a far-red PDZD2 channel if tissue autofluorescence crowds shorter wavelengths, and inspect unstained and single-color controls for bleed-through (general IF practice). For a nuclear or cytosolic epitope, test mild permeabilisation; for an accessible surface epitope, compare without it (general IF practice). Epitope location is unreported, and PDZD2 lacks a transmembrane segment (UniProt O15018 topology).
How do I separate PDZD2 signal from chromogenic background?
Run a no-primary section, block endogenous peroxidase before detection, and keep DAB development time identical across comparisons (general chromogenic IHC practice). Compare staining with the peptide-blocked heart image where that control can be reproduced; its caption reports peptide competition in paraffin-embedded human heart (selected A10309-1 caption). Diffuse color over folds, cut edges, or necrotic areas should be scored separately from intact cells (general IHC practice). If background rises after retrieval, shorten retrieval exposure around the pH 9.0, 20 min starting condition before altering several variables at once (page retrieval rule: nuclear antigen; general IHC practice). Record the compartment affected, because PDZD2 has several reported locations (UniProt O15018; HPA subcellular).
What is a defensible way to score PDZD2 IHC? ⚠ ANSWER MARKED FOR VERIFICATION
Predefine the cell population and compartment, then report the percentage of positive viable cells and an H-score from 0–300 using intensity grades 0–3 (general IHC practice). For dispersed positive cells, report positive-cell density per mm² of evaluable tissue instead (general IHC practice). Normalize comparisons to viable area or the counted cells of the same type, and keep retrieval, exposure, and DAB development consistent (general IHC practice). Report membrane, cytosol, and nuclear scores separately where visible, given the differing localisation records (HPA subcellular; UniProt O15018). Interpret small differences cautiously because HPA rates its tissue staining reliability uncertain (HPA tissue IHC).
When should an apparent PDZD2-positive cell be treated as an artefact?
Prioritize staining in intact cells with a reproducible compartment pattern and a peptide-competition response where available (general IHC practice; selected A10309-1 caption). Check cell identity: HPA reports medium staining in tonsil squamous epithelial cells and low staining in lung macrophages, but rates its tissue IHC reliability uncertain (HPA tissue IHC). A pattern confined to section edges, folds, or necrosis warrants review as a processing or staining artefact (general IHC practice). Brown pigment that persists in a no-primary control warrants investigation of endogenous enzyme activity or other background (general chromogenic IHC practice). An isolated compartment claim also needs review against PDZD2’s reported nuclear, cytoplasmic, endoplasmic reticulum, membrane, and cytosolic locations (UniProt O15018; HPA subcellular).
Boster reagents
Best PDZD2 / PDZ domain-containing protein 2 IHC Antibodies
A10309-1 has IHC data from paraffin-embedded human heart and IF data from HepG2 cells (catalog: image captions); listed reactivity covers human, mouse, and rat (catalog: reactivity).
Real IHC data
Anti-PDZD2/Pdzk3 Antibody
Cat # A10309-1
A10309-1 will render with its IHC figure from paraffin-embedded human heart, including a synthesized-peptide blocking image (catalog: IHC image caption). The same SKU lists IHC, IF, and ICC, with IF shown in HepG2 cells (catalog: applications and IF image caption).
Which to pick: For tissue IHC, choose A10309-1 at 1:100–1:300; its own figure shows paraffin-embedded human heart, but the fixative is unreported (catalog: IHC dilution and IHC image caption). For IF/ICC, choose A10309-1, a rabbit polyclonal listed for both applications at 1:200–1:1000; its IF example uses HepG2 cells (catalog: host, dilution_raw, applications, and IF image caption). For cross-species work, A10309-1 lists human, mouse, and rat reactivity; the pictured IHC example is human heart tissue (catalog: reactivity and IHC image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry O15018 (PDZD2_HUMAN, PDZ domain-containing protein 2).
- Human Protein Atlas. PDZD2 tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. PDZD2 subcellular location (ICC-IF): Mainly localized to the plasma membrane and cytosol..
- Human Protein Atlas. PDZD2 antibody validation summary (5 antibodies).
- miR-363 acts as a tumor suppressor in osteosarcoma cells by inhibiting PDZD2. Oncology reports 2019 — PMC6448123.
- PubMed PMID:11289102 — UniProt-cited evidence.
- PubMed PMID:9205841 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for PDZD2 (PDZ domain-containing protein 2). Expected localisation Mainly cytoplasmic staining in connective tissue (HPA tissue IHC). Antigen retrieval: Tris-EDTA pH 9.0 HIER, 95–98 °C, 20 min (rule: nuclear antigen). Validated IHC antibody: A10309-1 at 1:100 - 1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Tonsil (Squamous epithelial cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human heart tissue; fixative not specified (datasheet A10309-1); 2. Fixation: Image fixative and duration unreported (datasheet A10309-1); 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-induced epitope retrieval in Tris-EDTA buffer, pH 9.0 , 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-PDZD2, 1:100 - 1:300 (datasheet A10309-1); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Antibody staining has low concordance with RNA expression (HPA tissue IHC); Isoform / epitope: 2 isoforms; processed chain spans 2493–2839 . Check epitope location (UniProt); Regulation: No specific induction cue annotated (UniProt). Evidence: UniProt O15018, HPA tissue IHC · Uncertain, HPA ICC-IF · Mainly localized to the plasma membrane and cytosol., Datasheet A10309-1, PMC6448123. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/PDZD2/immunohistochemistry-ihc-guide.