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DDC / Aromatic-L-amino-acid decarboxylase · IHC design guide
Design Immunohistochemistry for DDC
Use renal proximal tubules as a positive reference when planning DDC IHC on paraffin sections (HPA tissue IHC). Score cytoplasmic staining with appropriate controls, mindful of reported presumed off-target binding (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
DDC 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 | Cytoplasmic in several tissues, strongest in renal tubules (HPA tissue IHC) | |
| Staining pattern | Renal proximal tubule cell bodies show cytoplasmic staining (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A01374-2) | |
| Positive control | Appendix+4 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) | |
| Caveat | Presumed off-target binding may complicate scoring (HPA tissue IHC) | |
| Regulation | Tissue-dependent; high in kidney (UniProt) | |
| Isoform / epitope | 4 isoforms; check epitope coverage (UniProt) |
Section 1
Recommended DDC IHC & IF Protocols
The catalog antibody protocol uses EDTA pH 8.0 heat retrieval (datasheet A01374-2). The published IHC options below report DDC staining in patient tissue (PMC10593861) and human ovarian sections (PMC5043631).
| Sample | Paraffin-embedded human kidney tissue; fixative not specified (datasheet A01374-2) |
| Fixation | Image fixative and duration unreported (datasheet A01374-2); 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 A01374-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01374-2) |
| Primary antibody | Rabbit anti-DDC, 2-5 μg/ml (datasheet A01374-2) |
| Primary incubation | Overnight at 4 °C (datasheet A01374-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A01374-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | DDC-positive staining in endocrine cells of appendix (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in several tissues, most abundant in renal tubules. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet A01374-2); the ovarian study reports retrieval but does not specify its conditions (PMC5043631).
Section 2
What Is the Expected DDC Staining Pattern?
DDC staining in paraffin section IHC is expected mainly in the cytoplasm, especially in renal proximal tubule cell bodies and intestinal endocrine cells (HPA tissue IHC: cytoplasmic profile; High in these cells). DDC has no annotated transmembrane segment or signal peptide (UniProt P20711 topology and processing). Interpret the pattern with care: HPA rates tissue IHC reliability Enhanced but reports presumed off target binding that was disregarded (HPA tissue IHC reliability).
| Strong cytoplasmic staining in renal proximal tubule cell bodies, with little signal in adjacent cells. | This matches a useful positive pattern: HPA reports High staining in proximal tubule cell bodies and describes renal tubules as its most abundant tissue staining (HPA tissue IHC). Compare cells within the section before judging overall stain strength (general IHC practice). |
| Predominantly nuclear, sharply membranous, or extracellular staining in a proposed positive cell. | These compartments do not match the reported cytoplasmic tissue pattern or the absence of a transmembrane segment and signal peptide (HPA tissue IHC; UniProt P20711 topology and processing). Treat the pattern as suspect; inspect controls and morphology before assigning DDC positivity (general IHC practice). |
| Strong staining in a cell type reported as undetected, such as adipocytes or esophageal squamous epithelium. | HPA reports DDC as Not detected in those specified cells (HPA tissue IHC). Consider nonspecific antibody binding or detection background, especially because HPA notes presumed off target binding in its tissue assessment (HPA tissue IHC reliability; general IHC practice). |
| Weak, widespread chromogen obscures cell boundaries or appears in a no primary antibody control. | A broad deposit is difficult to reconcile with HPA's cell restricted High examples (HPA tissue IHC). Signal in a no primary antibody control points toward detection chemistry or endogenous activity; inspect that control before scoring target staining (general IHC practice). |
| No visible signal in renal proximal tubule cell bodies on a run with otherwise readable morphology. | That is discordant with HPA's High proximal tubule staining and UniProt's high kidney expression (HPA tissue IHC; UniProt P20711 tissue specificity). Check the validated IHC conditions and run controls before interpreting the tissue as biologically negative (general IHC practice). |
💡Expected DDC appearanceCall a section positive when identifiable renal proximal tubule cell bodies show strong cytoplasmic staining, or intestinal endocrine cells show strong staining (HPA tissue IHC: High); predominant nuclear or broad cell independent color is suspect against the cytoplasmic profile (HPA tissue IHC; general IHC practice).
| Choice of positive and comparison cells | Kidney proximal tubule cell bodies offer a High, abundant tissue pattern; intestinal endocrine cells are also High, while adrenal glandular cells are Medium (HPA tissue IHC). Compare the named cell types rather than treating every cell in an organ as equally positive (general IHC practice). |
| Antibody evidence and limits | HPA lists HPA017742 as IHC Enhanced and rates the tissue profile Enhanced, while describing medium agreement with RNA and presumed off target binding (HPA antibody validation; HPA tissue IHC reliability). Agreement with the expected cells and compartment strengthens interpretation but does not make every stained cell specific (general IHC practice). |
| Protein form and compartment | UniProt lists 4 isoforms, one annotated chain spanning residues 1–480, no signal peptide, and no transmembrane segment (UniProt P20711 isoforms, processing and topology). These facts support checking cellular localization; they do not establish which isoforms an unspecified antibody detects or how fixation affects staining. |
| IF/ICC Q: should its pattern match tissue IHC? | A: HPA reports mainly actin filament localization, with additional primary cilium localization, in ICC-IF; its tissue IHC profile is cytoplasmic (HPA subcellular ICC-IF; HPA tissue IHC). Assess each application against its own evidence rather than requiring identical visual patterns. |
| Situation | Likely cause | Next action |
|---|---|---|
| The kidney positive control has no proximal tubule signal. | A failed staining run is possible; the expected High signal is documented for proximal tubule cell bodies (HPA tissue IHC; general IHC practice). | Verify the IHC-validated antibody, its specified dilution and the run's retrieval and detection controls; repeat under its documented IHC conditions (general IHC practice). No DDC-specific retrieval condition is supplied here. |
| Most nuclei stain more strongly than cytoplasm. | A nuclear dominant pattern conflicts with HPA's cytoplasmic tissue profile (HPA tissue IHC). | Check the hematoxylin counterstain and no primary antibody control, then reassess cellular boundaries before calling DDC positive (general IHC practice). |
| Undetected comparator cells stain strongly. | HPA reports Not detected staining in adipocytes and esophageal squamous cells and acknowledges presumed off target binding (HPA tissue IHC and reliability). | Compare staining with a known positive cell type and an appropriate negative control; withhold a DDC call if the discordant staining persists (HPA tissue IHC; general IHC practice). |
| Diffuse brown signal appears throughout the section. | Widespread deposit can reflect background or endogenous chromogenic detection activity rather than the reported cell restricted pattern (HPA tissue IHC; general IHC practice). | Inspect a no primary antibody control and review detection blocking and wash steps according to the assay reagents; score only clearly localized cellular signal (general IHC practice). |
| Intestinal staining seems patchy across neighboring cells. | HPA assigns High staining to endocrine cells in the small intestine, duodenum, colon and rectum, rather than to every epithelial cell (HPA tissue IHC). | Use morphology and the reported cell type to score discrete positive cells; avoid treating unstained neighboring cells as a failed run when controls pass (HPA tissue IHC; general IHC practice). |
| ICC-IF shows a filamentous or cilium-associated signal that looks unlike chromogenic tissue IHC. | HPA's ICC-IF localization is mainly actin filaments, with an additional primary cilium location; tissue IHC is described as cytoplasmic (HPA subcellular ICC-IF; HPA tissue IHC). | Judge the images against their application-specific HPA patterns and controls; do not use the ICC-IF pattern alone to reject a cell-restricted cytoplasmic IHC result (HPA subcellular ICC-IF; HPA tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing DDC staining
A01374-2 · IHCIHC analysis of DOPA decarboxylase/DDC using anti-DOPA decarboxylase/DDC antibody (A01374-2). DOPA decarboxylase/DDC was detected in a paraf
A01374 · IHCImmunohistochemistry of DDC in human lung tissue with DDC antibody at 2.5 μg/mL.
A01374 · IFImmunofluorescence of DDC in human lung tissue with DDC antibody at 20 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000132437-DDC/tissue/cerebral+cortex#imid_20046681
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000132437-DDC/tissue/colon#imid_20044079
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000132437-DDC/tissue/liver#imid_20044080
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000132437-DDC/tissue/kidney#imid_20044081
HPA · ICC-IF CACO-2Human Protein Atlas immunofluorescence, CACO-2, antibody HPA017742; green = DDC, blue = nucleus, red = microtubules.
HPA · ICC-IF CACO-2Human Protein Atlas immunofluorescence, CACO-2, antibody HPA017742; green = DDC, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for DDC IHC & IF
🧪Run kidney first: proximal tubule cell bodies should stain (HPA: High in kidney proximal tubules). Use adipose tissue as the negative tissue; adipocytes should lack staining (HPA: Not detected in adipocytes). On the kidney slide, assess neighboring cells outside the proximal tubules as internal negatives: they should lack specific staining, while the HPA row establishes positivity only for proximal tubules (HPA: High in proximal tubules).
Positive control tissue: Appendix (Endocrine cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show DDC in CACO-2, SH-SY5Y, U2OS, ASC52telo, RPTEC/TERT1, hTERT-RPE1 (serum starved), with annotated localisation: Actin filaments (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control and a concentration-matched rabbit immunoglobulin isotype control (caption: rabbit primary antibody); use DDC-knockout material as a biological negative if available. Block endogenous peroxidase in kidney before HRP/DAB detection, and check for endogenous biotin if using an avidin–biotin system (caption: kidney section with HRP/DAB detection; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the exact A01374-2 kidney caption does not state the fixative (caption: fixative not stated). The paraffin-section example used heat retrieval in EDTA at pH 8.0, but whether retrieval is required is unreported (caption: EDTA heat retrieval). The supplied evidence does not establish that frozen sections or IF are easier; for kidney IF, assess tubular autofluorescence with an unstained control (HPA: High in kidney proximal tubules; standard IF practice).
HPA tissue IHC evidence for DDC
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. 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 |
|---|---|---|---|---|
| Appendix | Endocrine cells | High | Protein (IHC) | HPA → |
| Cerebellum | Molecular layer - neuropil | High | Protein (IHC) | HPA → |
| Colon | Endocrine cells | High | Protein (IHC) | HPA → |
| Duodenum | Endocrine cells | High | Protein (IHC) | HPA → |
| Kidney | Proximal tubules (cell body) | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Cerebral cortex | Endothelial cells | Not detected | Protein (IHC) | HPA → |
| Cervix | Glandular cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced DDC IHC Tips
Troubleshoot DDC staining in paraffin sections by checking retrieval, controls, cell type and staining pattern before assigning a biological interpretation.
What retrieval should I start with when DDC staining is weak in paraffin sections?
Start with heat-mediated retrieval in EDTA at pH 8.0 for the catalog antibody (datasheet A01374-2). The demonstrated kidney-section workflow then used 2 μg/ml primary antibody overnight at 4°C, so compare weak staining with that documented starting condition before changing several variables together (datasheet A01374-2). Check whether renal proximal tubule cell bodies show the expected signal, and include a no-primary control to assess detection background (HPA: high in kidney proximal tubule cell bodies; standard IHC practice). If staining remains weak, compare an alternative retrieval buffer on adjacent sections while holding detection and imaging conditions constant (standard IHC practice).
How should I troubleshoot fixation-related loss of DDC signal?
The catalog image documents a paraffin-embedded human kidney section but does not state its fixative, so target-specific fixation sensitivity is unknown (datasheet A01374-2). Record the fixative and fixation duration for each specimen, then compare sections processed under known conditions with the same EDTA pH 8.0 retrieval (standard IHC practice; datasheet A01374-2). Use kidney proximal tubule cell bodies as an internal pattern check where present, and run a no-primary control alongside any altered processing condition (HPA: high in kidney proximal tubule cell bodies; standard IHC practice). Do not attribute a failed stain to DDC modification or topology without a controlled fixation comparison (UniProt P20711 processing and topology; standard IHC practice).
Where should DDC staining appear, and how should unusual patterns be checked?
In tissue IHC, expect predominantly cytoplasmic staining, with abundant signal in renal tubules and high staining in proximal tubule cell bodies (HPA: tissue IHC profile and kidney staining). DDC has no annotated transmembrane segment, signal peptide or propeptide, so a crisp membrane outline alone needs scrutiny rather than automatic acceptance (UniProt P20711 topology and processing). HPA also reports actin-filament and primary-cilium localisation from subcellular imaging; assess those finer patterns separately from the tissue IHC readout (HPA: subcellular localisation; HPA: tissue IHC profile). Compare suspicious nuclear, extracellular or diffuse tissue-wide staining with morphology, a no-primary control and an expected positive region on the same run (standard IHC practice; HPA: kidney staining).
Could DDC isoforms or epitope accessibility explain discordant IHC results?
DDC has 4 annotated isoforms, but the supplied product caption does not map this antibody’s epitope or establish which isoforms it detects (UniProt P20711 isoforms; datasheet A01374-2). Check the antibody’s immunogen or epitope documentation before assigning isoform specificity, and avoid interpreting a negative section as loss of every DDC isoform (standard IHC practice; UniProt P20711 isoforms). The annotated protein is a 480-residue chain with no signal peptide or transmembrane segment; those features alone do not establish epitope accessibility after processing (UniProt P20711 processing and topology). Compare adjacent sections using the documented EDTA pH 8.0 retrieval and a consistent primary-antibody condition before attributing discordance to splicing (datasheet A01374-2; standard IHC practice).
How can I use IF to investigate an ambiguous DDC IHC pattern?
On the separate IF/ICC guide, pair DDC with a marker that identifies the expected cell type, such as renal proximal tubule cells when examining kidney, and check colocalisation within cell bodies (HPA: high in kidney proximal tubule cell bodies; standard IF practice). Choose fluorophores after inspecting unstained tissue for autofluorescence, and place the weaker signal in a cleaner detection channel where possible (standard IF practice). Because DDC lacks an annotated transmembrane segment, test permeabilisation for access to intracellular epitopes while recognising that this antibody’s epitope location is unreported (UniProt P20711 topology; datasheet A01374-2; standard IF practice). Include single-label and no-primary controls before comparing IF patterns with chromogenic IHC (standard IF practice).
What should I change when DDC IHC has widespread brown background?
First compare the stained section with a no-primary control to separate primary-antibody staining from detection-system background (standard IHC practice). The documented kidney workflow used 10% goat serum blocking, 2 μg/ml primary overnight at 4°C, and a peroxidase-linked secondary for 30 minutes at 37°C (datasheet A01374-2). For DAB IHC, check the peroxidase block, washing and chromogen development when background is widespread; these are general workflow controls, not evidence of DDC-specific behaviour (standard IHC practice). Treat staining outside expected renal tubule cells cautiously because the tissue survey reported presumed off-target binding despite its Enhanced reliability rating (HPA: reliability description and kidney staining).
How should I quantify DDC staining across kidney sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the compartment before scoring: renal proximal tubule cell bodies are a documented high-staining region, and the tissue IHC profile is predominantly cytoplasmic (HPA: kidney staining and tissue IHC profile). On matched sections, report the percentage of positive cells and an H-score based on staining intensity, keeping the threshold and exposure or scan settings consistent (standard IHC practice). Normalise cell counts to the number of evaluable proximal tubule cells, or report positive-cell density per mm² of evaluable tissue when counts are impractical (standard IHC practice). Exclude damaged edges and poorly preserved regions by a prespecified rule, and retain a no-primary control for threshold setting (standard IHC practice).
How can I distinguish true DDC staining from an IHC artefact?
A convincing kidney result places signal in proximal tubule cell bodies with predominantly cytoplasmic staining, consistent with the reported tissue pattern (HPA: kidney staining and tissue IHC profile). DDC catalyses conversion of DOPA to dopamine and 5-hydroxytryptophan to serotonin, but brown staining alone does not measure that enzymatic activity (UniProt P20711 function; standard IHC interpretation). Treat isolated nuclear or extracellular signal, staining confined to section edges or necrotic areas, and signal in unexpected cells as prompts for control review (standard IHC practice; HPA: tissue IHC profile). Check no-primary and peroxidase-block controls for endogenous enzyme or detection artefacts before calling weak or widespread DAB signal DDC-positive (standard IHC practice).
Boster reagents
Best DDC / Aromatic-L-amino-acid decarboxylase IHC Antibodies
Two anti-DDC antibodies have human tissue IHC images (catalog captions: A01374, human lung; A01374-2, human kidney). A01374 also has a human lung IF image (catalog caption: A01374).
Real IHC data
Anti-DOPA decarboxylase/DDC Antibody ®
Cat # A01374-2
Real IHC data
Anti-DDC Antibody
Cat # A01374
A01374 will render with human lung IHC at 2.5 μg/mL; its catalog also lists IF and shows human lung IF at 20 μg/mL (catalog: A01374 applications and image captions). A01374-2 will render with human kidney paraffin-section IHC at 2 μg/mL (catalog: A01374-2 IHC caption).
Which to pick: For paraffin-section IHC, choose A01374-2: its kidney caption documents EDTA retrieval at pH 8.0 and DAB detection; the fixative is unreported (catalog: A01374-2 IHC caption). For IF, A01374 has a human lung tissue image, while ICC is not shown (catalog: A01374 IF caption and applications). Both list human, mouse and rat reactivity, but the supplied IHC and IF images show human tissue only; cross-species IHC performance remains unshown (catalog: reactivity and image captions for both SKUs).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P20711 (DDC_HUMAN, Aromatic-L-amino-acid decarboxylase).
- Human Protein Atlas. DDC tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. DDC subcellular location (ICC-IF): Mainly localized to the actin filaments. In addition localized to the primary cilium..
- Human Protein Atlas. DDC antibody validation summary (1 antibodies).
- The role of osteopontin and tumor necrosis factor alpha receptor-1 in xenobiotic-induced cholangitis and biliary fibrosis in mice. Laboratory investigation; a journal of technical methods and pathology 2010 — PMC4285781.
- RNA modification regulator DDC in endometrial cancer affects the tumor microenvironment and patient prognosis. Scientific reports 2023 — PMC10593861.
- L-DOPA in the hu man ovarian follicular fluid acts as an antioxidant factor on granulosa cells. Journal of ovarian research 2016 — PMC5043631.
- Analysis of Expression and Functional Activity of Aromatic L-Amino Acid Decarboxylase (DDC) and Serotonin Transporter (SERT) as Potential Sources of Serotonin in Mouse Ovary. International journal of molecular sciences 2019 — PMC6627913.
- PubMed PMID:2590185 — UniProt-cited evidence.
- PubMed PMID:1612608 — UniProt-cited evidence.
- PubMed PMID:1540578 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for DDC (Aromatic-L-amino-acid decarboxylase). Expected localisation Cytoplasmic in several tissues, strongest in renal tubules (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A01374-2). Validated IHC antibody: A01374-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Endocrine cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human kidney tissue; fixative not specified (datasheet A01374-2); 2. Fixation: Image fixative and duration unreported (datasheet A01374-2); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet A01374-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01374-2); 8. Primary antibody: Rabbit anti-DDC, 2-5 μg/ml (datasheet A01374-2); 9. Primary incubation: Overnight at 4 °C (datasheet A01374-2). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Caveat: Presumed off-target binding may complicate scoring (HPA tissue IHC); Isoform / epitope: 4 isoforms; check epitope coverage (UniProt); Regulation: Tissue-dependent; high in kidney (UniProt). Evidence: UniProt P20711, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the actin filaments. In addition localized to…, Datasheet A01374-2, PMC10593861, PMC5043631. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/DDC/immunohistochemistry-ihc-guide.