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CDA / Cytidine deaminase · IHC design guide
Design Immunohistochemistry for CDA
This guide covers CDA staining in paraffin sections with the catalog antibody (datasheet A01578-1). Bone marrow hematopoietic cells show medium staining, while the cellular compartment remains unestablished (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
CDA 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 | Cellular compartment not established (HPA tissue IHC) | |
| Staining pattern | Staining in a subset of immune cells; compartment unknown (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6 HIER, heat-mediated (datasheet A01578-1) | |
| Positive control | Bone marrow | |
| 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 | Immune-cell staining may complicate whole-tissue scoring (HPA tissue IHC) | |
| Regulation | High in granulocytes; low in monocytes (UniProt) | |
| Isoform / epitope | No isoforms or processing reported; one 1–146 chain (UniProt) |
Section 1
Recommended CDA IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol with published CDA IHC methods for lung and pancreatic tumors (PMC9440127; PMC7283477; PMC8056724).
| Sample | Paraffin-embedded human intestinal cancer tissue; fixative not specified (datasheet A01578-1) |
| Fixation | Image fixative and duration unreported (datasheet A01578-1); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Citrate pH 6, 20 min (datasheet A01578-1) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A01578-1) |
| Primary antibody | Rabbit anti-CDA, 1μg/ml (datasheet A01578-1) |
| Primary incubation | Overnight at 4 °C (datasheet A01578-1) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A01578-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | CDA-positive staining in hematopoietic cells of bone marrow (HPA tissue IHC: Medium). HPA tissue profile: Expression in a subset of immune cells. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated citrate retrieval at pH 6 for the catalog antibody (datasheet A01578-1), then assess staining with appropriate controls.
Section 2
What Is the Expected CDA Staining Pattern?
CDA staining in paraffin sections is expected in a subset of immune cells, with medium staining reported in bone marrow hematopoietic cells (HPA tissue IHC: Enhanced). Nucleoplasmic localization is supported by ICC-IF, but the tissue IHC record does not assign a compartment (HPA ICC-IF; HPA tissue IHC). CDA has no transmembrane segment (UniProt P32320 topology).
| A subset of bone marrow hematopoietic cells stains at medium intensity. | This matches the reported tissue IHC result (HPA tissue IHC: bone marrow, hematopoietic cells, Medium). The record does not identify which marrow cells stain; UniProt separately reports high expression in granulocytes (UniProt P32320 tissue specificity). |
| Staining appears nucleoplasmic in identifiable positive cells. | This is consistent with the approved ICC-IF location (HPA ICC-IF: nucleoplasm). Treat nuclear localization in paraffin sections as supportive, not definitive: the supplied tissue IHC profile does not annotate CDA's staining compartment (HPA tissue IHC). |
| The apparent signal is confined to membranes or extracellular material. | That pattern warrants an artefact check: CDA has no transmembrane segment or signal peptide (UniProt P32320 topology and processing). ICC-IF places CDA in the nucleoplasm (HPA ICC-IF), though that assay alone cannot define every tissue IHC pattern. |
| Adipocytes or listed negative epithelial or glandular cells stain strongly. | This conflicts with their reported 'Not detected' results (HPA tissue IHC: adipose adipocytes; bronchial respiratory epithelium; adrenal and appendix glandular cells). Check antibody specificity and chromogenic background before assigning the signal to CDA (general IHC practice). |
| Nearly every cell has diffuse staining, or known-positive marrow has no signal. | Uniform staining does not fit the reported subset-of-immune-cells profile; absent marrow signal conflicts with its Medium result (HPA tissue IHC). These observations require control and detection checks, but neither alone identifies the failure mechanism (general IHC practice). |
💡Expected CDA appearanceCall a result concordant when a subset of bone marrow hematopoietic cells shows medium staining (HPA tissue IHC), with nucleoplasmic signal supportive but not required by tissue evidence (HPA ICC-IF); strong, widespread staining of HPA-negative cell types is suspect (HPA tissue IHC).
| Tissue and cell selection | Bone marrow hematopoietic cells provide the reported medium-positive comparison; adipocytes in adipose tissue provide a reported negative comparison (HPA tissue IHC). Low staining in esophageal squamous cells, hepatocytes, splenic red-pulp cells or lymph-node non-germinal-center cells should not be treated as a strong positive benchmark (HPA tissue IHC). |
| Assay-specific localization evidence | Nucleoplasm is an approved ICC-IF location (HPA ICC-IF). Tissue IHC reports expression in a subset of immune cells without a compartment annotation (HPA tissue IHC); a mismatch in compartment merits review, not automatic rejection of the section. |
| Antibody validation | The listed antibody HPA064202 has Enhanced IHC and Approved ICC status (HPA antibodies). The tissue IHC reliability description reports medium consistency between antibody staining and RNA data and notes staining in unannotated cells or structures (HPA tissue IHC); interpret unexpected cells with that limitation in mind. |
| Protein architecture | CDA is a single 1–146 chain with no annotated signal peptide, propeptide, glycosylation sites or transmembrane segment (UniProt P32320 processing and topology). These facts do not establish how formalin fixation or antigen retrieval affects its IHC signal. |
| Situation | Likely cause | Next action |
|---|---|---|
| Bone marrow control has no convincing signal. | The expected comparison is missing (HPA tissue IHC: hematopoietic cells, Medium); the cause cannot be assigned from the record. | Check the section, primary antibody, detection reagents and counterstain with appropriate run controls (general IHC practice). Review retrieval against the antibody's validated IHC instructions; no CDA-specific retrieval condition is supplied. |
| Strong staining appears in adipocytes or bronchial respiratory epithelium. | Both are reported as Not detected (HPA tissue IHC); nonspecific primary binding or detection background is possible (general IHC practice). | Compare with a no-primary control and the known-positive marrow section; inspect whether the color follows cells or appears across the section (general IHC practice). |
| Brown color is widespread regardless of cell type. | A widespread pattern conflicts with subset-of-immune-cells expression (HPA tissue IHC). Endogenous enzyme activity or nonspecific detection can produce chromogenic background (general IHC practice). | Review the no-primary control, endogenous peroxidase block if using HRP, and detection reagent controls (general IHC practice). Reassess cell-specific signal only after background is controlled. |
| The only apparent signal is membranous or extracellular. | This is discordant with the nucleoplasmic ICC-IF location and the absence of a transmembrane segment or signal peptide (HPA ICC-IF; UniProt P32320 topology and processing). Tissue IHC does not specify a compartment (HPA tissue IHC). | Inspect the positive marrow control and no-primary control, then review morphology and antibody-specific staining before calling the signal CDA (general IHC practice). |
| Weak staining is seen in liver or esophageal epithelium. | Low staining is reported in hepatocytes and esophageal squamous epithelial cells (HPA tissue IHC); weak signal alone is not discordant. | Score the relevant cell type and compare it with the medium-positive marrow control and assay background (HPA tissue IHC; general IHC practice). Avoid interpreting tissue-wide intensity as a single result. |
| IF/ICC shows nucleoplasmic staining while paraffin IHC looks different. | The nucleoplasmic assignment comes from ICC-IF; tissue IHC has no annotated compartment (HPA ICC-IF; HPA tissue IHC). | Assess each assay against its own controls and cell-type evidence (general IHC practice). Use the ICC-IF location as a cross-check, without imposing an IF/ICC protocol or compartment rule on paraffin IHC. |
Experiment evidence
IHC & IF images showing CDA staining
A01578-1 · IHCIHC analysis of CDA using anti-CDA antibody (A01578-1). CDA was detected in paraffin-embedded section of human intestinal cancer tissue. Hea
A01578-1 · IHCIHC analysis of CDA using anti-CDA antibody (A01578-1). CDA was detected in paraffin-embedded section of human lung cancer tissue. Heat medi
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000158825-CDA/tissue/cerebral+cortex#imid_17774487
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000158825-CDA/tissue/colon#imid_17774413
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000158825-CDA/tissue/liver#imid_17774398
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000158825-CDA/tissue/kidney#imid_17774415
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA064202; green = CDA, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA064202; green = CDA, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for CDA IHC & IF
🧪Run bone marrow first; its hematopoietic cells should stain for CDA (HPA: Medium in bone marrow hematopoietic cells). Run adipose tissue as the negative tissue (HPA: Not detected in adipocytes); on the bone marrow slide, cells without specific staining should show only counterstain or background, but HPA does not identify a particular internal-negative cell type.
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 CDA in A-431, SiHa, U2OS, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control, a concentration-matched rabbit isotype control (selected SKU caption: rabbit primary antibody), and CDA-knockout material as a biological negative where available (standard IHC practice). Check endogenous peroxidase and biotin background in bone marrow because the illustrated detection uses a biotinylated secondary, streptavidin–biotin complex, and DAB (selected SKU caption).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected SKU tissue-IHC caption does not state the fixative. The caption uses citrate retrieval at pH 6 for 20 minutes on a paraffin section, but does not establish that retrieval is required (selected SKU caption). Frozen sections or IF are not established as easier by the supplied evidence; for IF, HPA reports nucleoplasmic localization in its ICC-IF images, while endogenous peroxidase or biotin background warrants attention for the illustrated bone marrow IHC detection method (HPA: Nucleoplasm; selected SKU caption: biotin-based DAB detection).
HPA tissue IHC evidence for CDA
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. 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 |
|---|---|---|---|---|
| Bone marrow | Hematopoietic 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 → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced CDA IHC Tips
Use the catalog antibody’s paraffin-section protocol as the IHC starting point, then judge staining by cell type, compartment, and controls (datasheet A01578-1; HPA tissue IHC; HPA subcellular).
Which retrieval conditions should I start with for CDA in paraffin sections?
Start with heat-mediated citrate buffer at pH 6 for 20 minutes (datasheet A01578-1). The selected paraffin-section example used those conditions with 1 μg/ml primary antibody overnight at 4°C, so keep those variables together for the first comparison (datasheet A01578-1). If staining is weak, compare a modest change in heating time on adjacent sections while holding detection and exposure to chromogen constant (standard IHC practice). Include a bone marrow section with hematopoietic cells and a no-primary control to distinguish weak target staining from background (HPA tissue IHC; standard IHC practice). Record nuclear and nonnuclear staining separately because nucleoplasmic localisation has been reported in cell imaging (HPA subcellular).
How should I troubleshoot CDA staining across differently fixed tissue blocks?
The selected image describes a paraffin-embedded human intestinal cancer section but does not report its fixative, so target-specific fixation sensitivity is unknown (datasheet A01578-1). Compare blocks with documented fixation histories using the same pH 6 citrate retrieval and antibody concentration before changing detection chemistry (datasheet A01578-1; standard IHC practice). Assess section integrity and staining in an internal or companion positive cell population, since variable fixation can alter accessible epitopes in paraffin sections (standard IHC practice). Do not assign a weak result to a particular fixative without a matched comparison, and retain a no-primary control for each condition (standard IHC practice). HPA tissue staining patterns do not establish fixation tolerance (HPA tissue IHC).
What staining compartment is plausible for CDA, and how should discordant patterns be assessed?
Nucleoplasmic localisation is reported from cell imaging, whereas the UniProt record supplies no subcellular annotation for CDA (HPA subcellular; UniProt P32320). CDA has no annotated transmembrane segment or signal peptide, so isolated crisp membrane or secretory-pattern staining warrants scrutiny rather than automatic assignment to CDA (UniProt P32320 topology and processing). Score nuclear and cytoplasmic chromogen separately within identifiable cells, using the same threshold across sections (standard IHC practice). Compare suspect patterns with no-primary controls and with hematopoietic cells in bone marrow, where medium staining is reported (standard IHC practice; HPA tissue IHC). Cell imaging is a localisation clue, not a tissue-section staining map (HPA subcellular; standard IHC practice).
Could isoforms or epitope masking explain an unexpected CDA staining pattern?
The supplied CDA record lists 0 isoforms, one chain spanning residues 1–146, and a CMP/dCMP-type deaminase domain at residues 13–140 (UniProt P32320). It also lists 0 glycosylation sites and 0 modified residues, but the catalog antibody’s precise epitope is not supplied (UniProt P32320; datasheet A01578-1). Therefore, test retrieval-dependent epitope accessibility with adjacent sections before proposing an isoform-specific explanation for lost chromogenic staining (standard IHC practice). Keep the initial pH 6 citrate condition as the reference and compare morphology as well as signal after any retrieval change (datasheet A01578-1; standard IHC practice). An absent signal cannot identify which residues were inaccessible (standard IHC practice).
How can I use IF to investigate ambiguous CDA IHC staining?
Use IF as a separate follow-up to the chromogenic paraffin-section result; the selected catalog example supplies IHC conditions, not an IF validation (datasheet A01578-1). Multiplex CDA with a validated granulocyte marker when examining the highly expressing population described in the record, and interpret overlap at the single-cell level (UniProt P32320 tissue specificity; standard IF practice). Choose a fluorophore channel after inspecting tissue autofluorescence and include single-label controls to assess bleed-through (standard IF practice). For an intracellular or nucleoplasmic epitope, compare an appropriate permeabilised condition with a minimally permeabilised control; no membrane-spanning region is annotated, while the antibody epitope itself is unspecified (UniProt P32320 topology; HPA subcellular; standard IF practice). Do not transfer the IHC incubation settings to IF without optimisation (datasheet A01578-1; standard IF practice).
What should I change when CDA IHC shows diffuse brown background?
First compare the section with a no-primary control and inspect whether brown signal tracks tissue edges, damaged areas, or broadly stained cells (standard IHC practice). The selected protocol used 10% goat serum blocking, 1 μg/ml primary antibody overnight at 4°C, a biotinylated secondary, and DAB development (datasheet A01578-1). Check endogenous peroxidase blocking and shorten chromogen development if the control is brown; these are general chromogenic IHC checks, not CDA-specific findings (standard IHC practice). Because the illustrated detection uses a biotin-based complex, assess endogenous biotin contribution when background follows tissue structures (datasheet A01578-1; standard IHC practice). Preserve genuine cell-restricted signal while adjusting washes or antibody concentration (HPA tissue IHC; standard IHC practice).
How should CDA-positive cells be quantified across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the scored compartment and cell population before measurement, then apply one staining threshold to all sections processed together (standard IHC practice). For a mixed population, report the percentage of positive cells and an intensity-based H-score within the selected cell type; for sparse immune cells, report positive-cell density per mm² of viable tissue (standard IHC practice). Normalise counts to the area assessed or to the total number of eligible cells, and record excluded necrotic and edge regions (standard IHC practice). CDA staining is reported in a subset of immune cells, with medium staining in bone marrow hematopoietic cells, so whole-section brown area can obscure cell-specific differences (HPA tissue IHC; standard IHC practice). Keep nuclear and cytoplasmic scores separate if both occur (HPA subcellular; standard IHC practice).
How can I distinguish true CDA staining from tissue or detection artefacts?
Give most weight to reproducible staining in identifiable cells that survives comparison with a no-primary control and a separately processed positive reference (standard IHC practice). Bone marrow hematopoietic cells show medium staining in the supplied tissue profile, while CDA is reported as highly expressed in granulocytes (HPA tissue IHC; UniProt P32320 tissue specificity). Nucleoplasmic signal is plausible from cell imaging, but isolated membrane outlines conflict with the absence of an annotated transmembrane segment and need independent checking (HPA subcellular; UniProt P32320 topology). Discount signal confined to section edges or necrotic areas, and investigate diffuse brown staining through peroxidase and biotin-related controls for the illustrated detection method (standard IHC practice; datasheet A01578-1). Report discordant compartments and cell types rather than collapsing them into one positive score (standard IHC practice).
Boster reagents
Best CDA / Cytidine deaminase IHC Antibodies
A01578-1 has IHC images from human cancer tissues and mouse intestine (catalog IHC image captions); its listed reactivity includes rat (catalog reactivity), but no IF/ICC data are provided (catalog applications and image captions).
Real IHC data
Anti-CDA Antibody ®
Cat # A01578-1
A01578-1 is listed for IHC and WB in human, mouse and rat (catalog applications and reactivity). Its IHC captions show paraffin sections of human intestinal, lung and mammary cancers and mouse intestine (catalog IHC image captions).
Which to pick: Choose A01578-1 for tissue IHC: it is a rabbit polyclonal antibody listed for IHC (catalog host, clonality and applications), with images from paraffin sections (catalog IHC image captions). Its listed reactivity supports considering human, mouse and rat samples, although the IHC images show only human and mouse tissue (catalog reactivity and IHC image captions). No IF/ICC application or image is reported for A01578-1 (catalog applications and image captions); the paraffin-section captions do not report the fixative (catalog IHC image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P32320 (CDD_HUMAN, Cytidine deaminase).
- Human Protein Atlas. CDA tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. CDA subcellular location (ICC-IF): Localized to the nucleoplasm..
- Human Protein Atlas. CDA antibody validation summary (1 antibodies).
- DNA methylome and single-cell transcriptome analyses reveal CDA as a potential druggable target for ALK inhibitor-resistant lung cancer therapy. Experimental & molecular medicine 2022 — PMC9440127.
- Scheduling nab-paclitaxel combined with gemcitabine as first-line treatment for metastatic pancreatic adenocarcinoma. British journal of cancer 2020 — PMC7283477.
- Chemotherapy-induced CDA expression renders resistant non-small cell lung cancer cells sensitive to 5'-deoxy-5-fluorocytidine (5'-DFCR). Journal of experimental & clinical cancer research : CR 2021 — PMC8056724.
- hENT1 Predicts Benefit from Gemcitabine in Pancreatic Cancer but Only with Low CDA mRNA. Cancers 2021 — PMC8616255.
- PubMed PMID:7923172 — UniProt-cited evidence.
- PubMed PMID:9878810 — UniProt-cited evidence.
- PubMed PMID:9596658 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for CDA (Cytidine deaminase). Expected localisation Cellular compartment not established (HPA tissue IHC). Antigen retrieval: Citrate pH 6 HIER, heat-mediated (datasheet A01578-1). Validated IHC antibody: A01578-1 at 1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Bone marrow (Hematopoietic cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human intestinal cancer tissue; fixative not specified (datasheet A01578-1); 2. Fixation: Image fixative and duration unreported (datasheet A01578-1); 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 retrieval: Citrate pH 6 , 20 min (datasheet A01578-1); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A01578-1); 8. Primary antibody: Rabbit anti-CDA, 1μg/ml (datasheet A01578-1); 9. Primary incubation: Overnight at 4 °C (datasheet A01578-1). Watch for: Fixation: Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific); Caveat: Immune-cell staining may complicate whole-tissue scoring (HPA tissue IHC); Isoform / epitope: No isoforms or processing reported; one 1–146 chain (UniProt); Regulation: High in granulocytes; low in monocytes (UniProt). Evidence: UniProt P32320, HPA tissue IHC · Enhanced, HPA ICC-IF · nucleoplasm., Datasheet A01578-1, PMC9440127, PMC7283477. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/CDA/immunohistochemistry-ihc-guide.