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SRD5A3 / Polyprenal reductase · IHC design guide
Design Immunohistochemistry for SRD5A3
Plan SRD5A3 chromogenic IHC in paraffin sections using the reported cytoplasmic tissue pattern (HPA tissue IHC) and ER membrane location (UniProt). The catalog antibody has a formalin-fixed prostate carcinoma IHC example (A08082 IHC-P caption); interpret staining with HPA’s uncertain reliability rating (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SRD5A3 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 tissue staining (HPA tissue IHC); ER membrane (UniProt) | |
| Staining pattern | General cytoplasmic staining across cell types (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | Bone marrow+3 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Formalin-fixed paraffin sections were used (A08082 IHC-P caption). (selected-SKU IHC image A08082) | |
| Caveat | Staining reliability is uncertain; RNA concordance is moderate (HPA tissue IHC) | |
| Regulation | Overexpressed in hormone-refractory prostate cancer (UniProt) | |
| Isoform / epitope | No annotated isoforms or processing; C-terminal tail is cytoplasmic (UniProt) |
Section 1
Recommended SRD5A3 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by published SRD5A3 staining methods for liver and prostate cancer tissues (PMC7803539; PMC7304221).
| Sample | FFPE human prostate carcinoma tissue (datasheet A08082) |
| Fixation | Image formalin-fixed; duration unreported (datasheet A08082); 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-SRD5A3, 1:10-1:50 (datasheet A08082) |
| 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 | SRD5A3-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 HIER at 95–98 °C for 20 min (page retrieval rule). Both published protocols also use pH 6 retrieval (PMC7803539; PMC7304221).
Section 2
What Is the Expected SRD5A3 Staining Pattern?
SRD5A3 is an endoplasmic reticulum membrane protein with 6 transmembrane segments (UniProt Q9H8P0 topology). In paraffin-section IHC, expect cytoplasmic staining in selected cells, including adrenal and gallbladder glandular cells and cerebellar granular-layer cells (HPA tissue IHC: Medium; general cytoplasmic expression). Treat the pattern as provisional: HPA rates tissue IHC reliability Uncertain because antibody staining and RNA expression have medium consistency (HPA tissue IHC: reliability).
| Cytoplasmic staining in adrenal or gallbladder glandular cells, with a low-background counterstained section. | This fits the reported IHC pattern: both cell populations have Medium staining, and the overall profile is generally cytoplasmic (HPA tissue IHC). Compare intensity within the same staining run; HPA levels describe its observations, not a universal threshold for every laboratory or section (HPA tissue IHC: Medium; reliability Uncertain). |
| Predominantly nuclear staining, with little cytoplasmic signal in the expected cells. | This conflicts with the reported IHC pattern and membrane topology (HPA tissue IHC: general cytoplasmic expression; UniProt Q9H8P0 topology). Check whether the signal tracks the counterstain or appears in a no-primary control before interpreting it as SRD5A3 (general IHC practice). |
| Strong staining in bone-marrow hematopoietic cells or splenic red-pulp cells. | HPA reports these populations as Not detected (HPA tissue IHC). Investigate cross-reactivity or endogenous chromogenic activity, especially if a no-primary control also stains (general IHC practice). Because HPA rates tissue IHC Uncertain, discordance alone cannot prove that every stained cell is a false positive (HPA tissue IHC: reliability). |
| Diffuse color across cells and surrounding tissue, obscuring cellular boundaries. | This cannot establish the reported cytoplasmic pattern (HPA tissue IHC: general cytoplasmic expression). Background may reflect detection chemistry or nonspecific staining; assess a no-primary control and the distribution of color before scoring cells (general IHC practice). |
| No signal in adrenal glandular cells while the section and counterstain are intact. | Adrenal glandular cells are a practical Medium-staining reference in HPA, although its IHC reliability is Uncertain (HPA tissue IHC). Check controls and assay conditions before calling the specimen negative; one unstained section does not overturn the reported tissue pattern (general IHC practice; HPA tissue IHC). |
💡Expected SRD5A3 appearanceCall a positive result when discernible cytoplasmic chromogen marks the relevant cells at an intensity comparable to a same-run HPA Medium reference, such as adrenal glandular cells (HPA tissue IHC: general cytoplasmic expression; adrenal glandular cells Medium); dominant nuclear color, broad background, or equally strong color in HPA Not detected populations warrants investigation before scoring (HPA tissue IHC; general IHC practice).
| Membrane topology and visible compartment | SRD5A3 spans the endoplasmic reticulum membrane 6 times (UniProt Q9H8P0 topology). HPA describes tissue IHC as generally cytoplasmic, so score the cellular pattern seen by chromogenic IHC rather than inferring that individual membrane segments are resolvable on the section (HPA tissue IHC; general IHC practice). |
| Choice of tissue reference | HPA records Medium staining in adrenal and gallbladder glandular cells and Not detected staining in bone-marrow hematopoietic cells and splenic red-pulp cells (HPA tissue IHC). Use these as comparison patterns, with the stated Uncertain reliability in view; they are not guaranteed positive or negative controls for every run (HPA tissue IHC: reliability; general IHC practice). |
| Antibody evidence | The listed antibody HPA027006 has an Uncertain IHC assessment (HPA antibodies: HPA027006). HPA also assigns the tissue profile Uncertain reliability because staining and RNA expression have medium consistency (HPA tissue IHC). Interpret a plausible cellular pattern alongside controls rather than treating staining intensity alone as confirmation (general IHC practice). |
| IF/ICC: should its location match tissue IHC? | HPA reports approved plasma-membrane and cytosol localization by ICC-IF, while its tissue IHC summary is generally cytoplasmic (HPA subcellular ICC-IF; HPA tissue IHC). These are different observations in different preparations; the ICC-IF result does not make plasma-membrane staining a required positive pattern in paraffin-section IHC (HPA subcellular ICC-IF; HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| The expected cytoplasmic cells are unstained. | The result may reflect an unsuccessful staining run or weak specimen signal; adrenal glandular cells are Medium in HPA, but its IHC reliability is Uncertain (HPA tissue IHC; general IHC practice). | Check a same-run reference section, reagent controls and chromogen development; then review the validated IHC workflow before interpreting the test section as negative (general IHC practice). |
| Nuclei carry most of the chromogen. | A nuclear-dominant pattern disagrees with HPA's general cytoplasmic IHC profile and UniProt's endoplasmic reticulum membrane assignment (HPA tissue IHC; UniProt Q9H8P0). | Inspect the no-primary control and counterstain, then rescore only specific cellular staining that remains distinct from background (general IHC practice). |
| Bone-marrow hematopoietic cells stain as strongly as the chosen reference. | Those cells are Not detected in the HPA tissue profile, although the profile has Uncertain reliability (HPA tissue IHC). Cross-reactivity or endogenous detection activity is possible (general IHC practice). | Compare a no-primary control and a same-run reference section. Investigate any persistent discordant pattern before assigning SRD5A3 positivity (general IHC practice). |
| Color appears throughout the section, including areas outside recognizable cells. | Diffuse background obscures the cellular pattern needed to assess HPA's general cytoplasmic observation (HPA tissue IHC). Nonspecific reagent binding or detection background are possible (general IHC practice). | Check no-primary controls; review blocking, washes, detection reagents and chromogen development, then repeat scoring on a clear section (general IHC practice). |
| Some expected cells stain, but the distribution varies across a section. | Uneven staining can arise from section handling or reagent coverage (general IHC practice). HPA's Medium designation does not specify a uniform signal in every cell (HPA tissue IHC). | Compare intact areas and the same-run reference, inspect section quality, and score only interpretable cells while recording the variation (general IHC practice). |
| A plasma-membrane outline appears, but cytoplasmic chromogen is absent. | HPA approves plasma-membrane localization for ICC-IF; its tissue IHC summary instead reports general cytoplasmic expression (HPA subcellular ICC-IF; HPA tissue IHC). | Evaluate the paraffin section against its IHC controls and cellular context. Do not use the ICC-IF location alone to call this an expected tissue IHC positive (HPA subcellular ICC-IF; HPA tissue IHC; general IHC practice). |
Experiment evidence
IHC & IF images showing SRD5A3 staining
A08082 · IHCSRD5A3 Antibody (C-term) (Cat. #A08082) IHC analysis in formalin fixed and paraffin embedded human prostate carcinoma followed by peroxidase
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000128039-SRD5A3/tissue/cerebral+cortex#imid_6720832
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000128039-SRD5A3/tissue/colon#imid_6713702
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000128039-SRD5A3/tissue/liver#imid_6713703
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000128039-SRD5A3/tissue/kidney#imid_6713696
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA027006; green = SRD5A3, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA027006; green = SRD5A3, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SRD5A3 IHC & IF
🧪Run adrenal gland first and expect staining in glandular cells (HPA: Medium in adrenal gland glandular cells). Use bone marrow hematopoietic cells as the negative tissue (HPA: Not detected); on the adrenal slide, adjacent cells without specific staining should show only background, but their negative status must be established rather than assumed (HPA: glandular cells are the annotated positive population).
Positive control tissue: Adrenal gland (Glandular cells, HPA Medium)
Negative control tissue: Bone marrow (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SRD5A3 in A-431, U-251MG, U2OS, with annotated localisation: Plasma membrane (approved), Cytosol (approved) (HPA subcellular).
Technical controls: Include no-primary (secondary-only) and host- and clonality-matched isotype controls, plus SRD5A3 knockout material or an immunogen-peptide competition control if available (standard IHC practice). Quench endogenous peroxidase and check the adrenal section for pigment that could be mistaken for DAB signal (standard chromogenic IHC practice).
⚠️Feasibility: The selected-SKU caption reports formalin-fixed, paraffin-embedded prostate carcinoma stained with a peroxidase-conjugated secondary and DAB (caption: A08082), but gives no target-specific fixation duration or window. Antigen-retrieval dependence is unreported in the supplied evidence; the caption alone does not establish whether frozen sections or IF would be easier. In adrenal sections, distinguish any endogenous pigment from specific chromogenic staining (standard IHC practice).
HPA tissue IHC evidence for SRD5A3
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Lymphoid tissue | Medium | Protein (IHC) | HPA → |
| Caudate | Neuronal cells | Medium | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Medium | Protein (IHC) | HPA → |
| Cerebral cortex | Neuronal cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Cervix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Spleen | Cells in red pulp | Not detected | Protein (IHC) | HPA → |
| Vagina | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SRD5A3 IHC Tips
Troubleshoot SRD5A3 staining in paraffin sections by checking retrieval, compartment pattern, controls and scoring before interpreting chromogenic signal.
How should I retrieve SRD5A3 in paraffin sections when staining is weak?
Start with citrate buffer at pH 6.0 for heat-induced retrieval at 95–98 °C for 20 min (page retrieval rule: cytoplasmic / membrane antigen). Allow sections to cool in buffer, then compare a retrieved section with an otherwise matched section so changes in signal can be attributed to retrieval (standard IHC practice). The catalog antibody stains formalin-fixed, paraffin-embedded human prostate carcinoma with peroxidase detection and DAB, but its caption does not specify retrieval conditions (A08082 tissue-IHC caption). If staining remains weak, test a more alkaline retrieval buffer on adjacent sections while watching for tissue damage and increased background (standard IHC practice).
Could fixation be causing weak or uneven SRD5A3 staining?
SRD5A3-specific sensitivity to fixation duration is unknown from the supplied evidence; do not infer it from tissue staining patterns or protein topology (supplied fixation rule). The catalog antibody has been used on formalin-fixed, paraffin-embedded human prostate carcinoma, but the image caption gives no fixation duration (A08082 tissue-IHC caption). Compare sections with documented processing histories using the same pH 6.0, 95–98 °C, 20 min retrieval and staining run (page retrieval rule; standard IHC practice). Examine morphology and internal tissue controls before assigning a weak result to fixation, because section handling and detection can also affect chromogenic intensity (standard IHC practice).
What staining compartment should I expect for SRD5A3?
Expect intracellular staining compatible with an endoplasmic reticulum membrane protein, rather than treating any single chromogenic pattern as definitive (UniProt Q9H8P0 subcellular location; standard IHC interpretation). SRD5A3 has 6 predicted transmembrane segments, so fine cytoplasmic or perinuclear signal is biologically plausible in paraffin sections (UniProt Q9H8P0 topology; standard IHC interpretation). HPA describes general cytoplasmic tissue staining, while its cell imaging lists plasma membrane and cytosol as approved locations (HPA tissue IHC; HPA subcellular). Check whether signal follows intact cell boundaries and intracellular morphology; diffuse extracellular deposits or isolated nuclear staining require independent validation before being called SRD5A3 (standard IHC practice; UniProt Q9H8P0 subcellular location).
How does the C-terminal epitope affect interpretation of staining?
The catalog antibody is described as C-terminal, while the supplied sequence places residues 282–318 on the cytoplasmic side of the membrane (A08082 tissue-IHC caption; UniProt Q9H8P0 topology). Record the exact immunogen sequence if available before judging whether a variant or processing event could remove the recognized epitope (standard IHC practice). The record lists a single 1–318 chain, no annotated isoforms and no annotated glycosylation or modified residues; these annotations do not establish antibody specificity (UniProt Q9H8P0 processing, isoforms and PTMs; standard IHC interpretation). Compare staining with an independent antibody to a different epitope, or a validated loss-of-target control, when specificity is consequential (standard IHC practice).
How should I follow up a chromogenic result with IF?
Treat IF as a separately optimized application: the supplied catalog image establishes chromogenic staining in formalin-fixed, paraffin-embedded human prostate carcinoma, not an IF protocol (A08082 tissue-IHC caption). In multiplex IF, pair SRD5A3 with a validated marker for the cell population being evaluated, and check each channel alone for bleed-through (standard IF practice). Choose a fluorophore whose emission is distinguishable from the specimen’s autofluorescence, and include an unstained section to assess that background (standard IF practice). Because the described C-terminal region is cytoplasmic, optimize permeabilisation to expose that side while preserving cellular structure; confirm the antibody’s actual epitope sequence before relying on this inference (A08082 tissue-IHC caption; UniProt Q9H8P0 topology; standard IF practice).
How can I reduce diffuse DAB background without losing SRD5A3 signal?
First inspect a no-primary control and a matched section stained with the primary antibody to separate detection background from antibody-dependent signal (standard IHC practice). For peroxidase-based DAB detection, block endogenous peroxidase, use an appropriate protein block and rinse thoroughly between steps (standard IHC practice; A08082 tissue-IHC caption: peroxidase and DAB). Titrate the IHC-validated antibody on adjacent sections rather than assuming the image caption supplies a working dilution; it does not (A08082 tissue-IHC caption; standard IHC practice). Recheck retrieval at pH 6.0, 95–98 °C for 20 min, since excessive treatment can compromise morphology and make background harder to interpret (page retrieval rule; standard IHC practice).
How should I quantify SRD5A3 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cellular compartment and eligible tissue area before scoring, then apply the same rules to every slide (standard IHC practice; UniProt Q9H8P0 subcellular location). For cellular chromogenic staining, report an H-score using intensity categories 0–3 weighted by the percentage of positive cells, or report the percentage positive at a prespecified threshold (standard IHC practice). If counting discrete positive cells, express density per mm² of viable tissue and exclude folds, necrosis and tissue edges consistently (standard IHC practice). Normalize comparisons to the same cell population, viable area, staining batch and detection settings; HPA’s uncertain tissue-IHC reliability warrants restraint when interpreting small differences (standard IHC practice; HPA tissue IHC reliability).
When is a positive SRD5A3 IHC result convincing?
A convincing result follows intact cells in a plausible intracellular or membrane-associated pattern and is reproducible on adjacent sections (UniProt Q9H8P0 subcellular location; standard IHC practice). Interpret it in the identified cell population: HPA reports medium staining in adrenal glandular cells and several neuronal populations, yet assigns its tissue IHC an uncertain reliability rating (HPA tissue IHC). Treat isolated nuclear signal, edge staining, necrotic deposits and signal retained in a no-primary peroxidase control as possible artefacts (UniProt Q9H8P0 subcellular location; standard IHC practice). The catalog prostate carcinoma image demonstrates staining, but its caption explicitly says clinical relevance has not been evaluated; do not use staining alone as a clinical conclusion (A08082 tissue-IHC caption).
Boster reagents
Best SRD5A3 / Polyprenal reductase IHC Antibodies
The catalog includes one human-reactive anti-SRD5A3 antibody with IHC-P data from human prostate carcinoma (catalog: A08082 reactivity and applications; A08082 image caption).
Real IHC data
Anti-SRD5A3 Antibody (C-term)
Cat # A08082
A08082 is listed for human IHC-P (catalog: A08082 applications and reactivity). Its image shows formalin-fixed, paraffin-embedded human prostate carcinoma stained using a peroxidase-conjugated secondary antibody and DAB (A08082 image caption).
Which to pick: For tissue IHC, choose A08082, a rabbit polyclonal antibody listed for IHC-P at 1:10–1:50 (catalog: A08082 host, dilution and applications). Its IHC image uses formalin-fixed, paraffin-embedded human prostate carcinoma (A08082 image caption). The catalog lists no IF/ICC application or non-human reactivity for A08082, so it offers no supported IF/ICC or cross-species pick (catalog: A08082 applications and reactivity).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9H8P0 (SR5A3_HUMAN, Polyprenal reductase).
- Human Protein Atlas. SRD5A3 tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. SRD5A3 subcellular location (ICC-IF): Localized to the plasma membrane and cytosol..
- Human Protein Atlas. SRD5A3 antibody validation summary (1 antibodies).
- Over-expression of SRD5A3 and its prognostic significance in breast cancer. World journal of surgical oncology 2021 — PMC8408928.
- Steroid 5 alpha-reductase 3 (SRD5A3) promotes tumor growth and predicts poor survival of human hepatocellular carcinoma (HCC). Aging 2020 — PMC7803539.
- Early upregulation of AR and steroidogenesis enzyme expression after 3 months of androgen-deprivation therapy. BMC urology 2020 — PMC7304221.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:15815621 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SRD5A3 (Polyprenal reductase). Expected localisation Cytoplasmic tissue staining (HPA tissue IHC); ER membrane (UniProt). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A08082 at 1:10-1:50 (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative Bone marrow. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: FFPE human prostate carcinoma tissue (datasheet A08082); 2. Fixation: Image formalin-fixed; duration unreported (datasheet A08082); 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-SRD5A3, 1:10-1:50 (datasheet A08082); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Formalin-fixed paraffin sections were used (A08082 IHC-P caption). (selected-SKU IHC image A08082); Caveat: Staining reliability is uncertain; RNA concordance is moderate (HPA tissue IHC); Isoform / epitope: No annotated isoforms or processing; C-terminal tail is cytoplasmic (UniProt); Regulation: Overexpressed in hormone-refractory prostate cancer (UniProt). Evidence: UniProt Q9H8P0, HPA tissue IHC · Uncertain, HPA ICC-IF · plasma membrane and cytosol., Datasheet A08082, PMC7803539, PMC7304221. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SRD5A3/immunohistochemistry-ihc-guide.