This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
BTD / Biotinidase · IHC design guide
Design Immunohistochemistry for BTD
Plan chromogenic BTD IHC in paraffin sections around the reported endothelial membrane pattern (HPA tissue IHC). Start the IHC-validated antibody at 1:100–1:200 (datasheet), and interpret staining in light of the uncertain tissue-IHC reliability (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
BTD 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 | Observed endothelial membranes (HPA tissue IHC); expected extracellular space (UniProt) | |
| Staining pattern | Membranous staining in endothelial cells (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Breast+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 paraffin sections (standard IHC practice; not target-specific) | |
| Caveat | Secreted BTD may make staining diverge from local RNA (HPA tissue IHC) | |
| Regulation | Liver-enhanced RNA; staining uncertain (HPA tissue RNA + IHC) | |
| Isoform / epitope | 4 isoforms; cleavage of signal peptide 1–21 affects N-terminal epitope planning (UniProt) |
Section 1
Recommended BTD IHC & IF Protocols
Compare the catalog antibody’s IHC-P protocol (datasheet) with published BTD staining of breast cancer patient paraffin sections (PMC12183389).
| Sample | Paraffin-embedded rat brain tissue; fixative not specified (datasheet A03020) |
| Fixation | Image fixative and duration unreported (datasheet A03020); 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-BTD, 1:100-1:200 (datasheet A03020) |
| 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 | BTD-positive staining in myoepithelial cells of breast (HPA tissue IHC: High). HPA tissue profile: Membranous expression in endothelial cells. 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); the published pH 9.0 protocol offers another condition to test (PMC12183389).
Section 2
What Is the Expected BTD Staining Pattern?
BTD is a secreted protein with no transmembrane segment, so extracellular staining is plausible; a membrane-associated signal does not establish that BTD is membrane anchored (UniProt P43251). HPA reports a membranous endothelial profile, high staining in breast myoepithelial cells and kidney glomerular cells, and medium staining in hepatocytes (HPA tissue IHC). These are provisional expectations because HPA rates its tissue staining Uncertain (HPA tissue IHC).
| Distinct endothelial membrane-associated staining, with stronger signal in breast myoepithelial cells or kidney glomerular cells. | This is broadly consistent with the reported endothelial profile and High staining in those two cell populations (HPA tissue IHC). Score the named cells separately from nearby structures; HPA's Uncertain reliability means a matching image supports an interpretation but does not independently validate antibody specificity (HPA tissue IHC). |
| Strong nuclear staining dominates the section while the reported cell populations show little signal. | A dominant nuclear pattern conflicts with the secreted, extracellular annotation and lacks support from the reported endothelial profile (UniProt P43251; HPA tissue IHC). Treat it as a possible artefact, inspect the no-primary control, and compare morphology before assigning BTD positivity (general IHC practice). |
| Adipocytes, marrow hematopoietic cells, or bronchial respiratory epithelial cells stain prominently. | HPA reports BTD as Not detected in those specific cells, so strong staining warrants scrutiny for cross-reactivity or endogenous detection activity (HPA tissue IHC; general IHC practice). The HPA result does not prove every cell in those tissues must be negative; compare the stained cell identity and control slide (HPA tissue IHC; general IHC practice). |
| Colour spreads across tissue compartments or appears similarly in cells with different reported staining levels. | Poorly confined signal is difficult to reconcile with the cell-specific HPA observations (HPA tissue IHC). Check a no-primary control for detection background and examine section edges or damaged areas before scoring; extracellular BTD can complicate a strict cell-boundary interpretation (general IHC practice; UniProt P43251). |
| No signal appears in breast myoepithelial cells or kidney glomerular cells. | Those cells are reported High, making them useful comparison sites, but HPA calls the overall tissue result Uncertain (HPA tissue IHC). First confirm tissue identity and preservation, then check the antibody's IHC-P instructions, control performance, retrieval and detection; absence alone cannot establish that the specimen lacks BTD (general IHC practice). |
💡Expected BTD appearanceA plausible positive is a localized endothelial membrane-associated profile with High staining in breast myoepithelial or kidney glomerular cells and Medium staining in hepatocytes; dominant nuclear colour or strong staining in HPA Not detected cells is suspect, and every comparison remains provisional because tissue reliability is Uncertain (HPA tissue IHC; UniProt P43251).
| Secreted protein and topology (UniProt P43251). | BTD has a signal peptide at residues 1–21 and no transmembrane segment; interpret membrane-associated colour alongside possible extracellular signal, without calling it an integral membrane protein (UniProt P43251). |
| Antibody and tissue evidence (HPA tissue IHC; HPA antibody record). | HPA lists HPA052275 IHC as Uncertain and reports low consistency between antibody staining and RNA expression; use the tissue pattern as a comparison, not proof of specificity (HPA tissue IHC; HPA antibody record). |
| Liver RNA and protein observations (HPA tissue IHC). | Liver is RNA tissue enhanced, while hepatocyte staining is Medium; secretion can separate the locations of RNA and protein, so RNA abundance does not predict slide intensity directly (HPA tissue IHC; UniProt P43251). |
| Protein processing and variants (UniProt P43251). | The mature chain spans residues 22–523, four isoforms are listed, and six glycosylation sites are annotated; the supplied record gives no antibody epitope, so variant coverage and epitope accessibility cannot be inferred (UniProt P43251). |
| Chromogenic detection chemistry (general IHC practice). | Avidin–biotin detection can produce signal from endogenous biotin in some tissues; a no-primary control and a detection system without avidin–biotin chemistry can help test that possibility (general IHC practice). |
| IF/ICC expectation (HPA subcellular; UniProt P43251). | HPA summarizes BTD as Secreted but provides no main ICC-IF location or cell-line images; an intracellular IF pattern therefore has no supplied HPA image benchmark (HPA subcellular; UniProt P43251). |
| Situation | Likely cause | Next action |
|---|---|---|
| Breast myoepithelial or kidney glomerular cells are blank (HPA tissue IHC). | The staining run may lack sensitivity, or the expected HPA pattern may not reproduce in this specimen (general IHC practice; HPA tissue IHC). | Verify cell identity and control-slide performance; review the IHC-validated antibody's stated retrieval, dilution and detection conditions before interpreting a negative (general IHC practice). |
| Nuclei are the main positive structures (UniProt P43251). | This compartment is unsupported for secreted BTD; nonspecific staining or detection artefact is possible (UniProt P43251; general IHC practice). | Compare with a no-primary control, reassess counterstain versus chromogen, and withhold a BTD-positive score until the pattern is resolved (general IHC practice). |
| Not detected cell types stain strongly (HPA tissue IHC). | Cross-reactivity or endogenous detection activity may explain discordant cell staining (HPA tissue IHC; general IHC practice). | Confirm the stained cell type against morphology, inspect the no-primary control, and compare with a reported positive population on a separate section (general IHC practice; HPA tissue IHC). |
| Broad colour obscures cell boundaries (general IHC practice). | Detection background, tissue damage, or genuinely extracellular material can blur localization; appearance alone cannot distinguish these explanations (general IHC practice; UniProt P43251). | Check the no-primary control and section integrity; score only interpretable regions and avoid assigning diffuse colour to a specific cell type (general IHC practice). |
| Liver is weaker than breast or kidney (HPA tissue IHC). | HPA reports Medium hepatocyte staining but High staining in breast myoepithelial and kidney glomerular cells (HPA tissue IHC). | Compare like-for-like runs and cell populations; do not raise the hepatocyte score solely because liver RNA is tissue enhanced (HPA tissue IHC; general IHC practice). |
| An IF/ICC image appears predominantly intracellular (HPA subcellular). | HPA has no ICC-IF images or assigned main location for BTD, so that pattern lacks a supplied image reference (HPA subcellular). | Treat the location as unverified and assess appropriate IF controls in the separate IF/ICC workflow; do not transfer an IHC-P appearance into an IF expectation (general IF practice; HPA subcellular). |
Experiment evidence
IHC & IF images showing BTD staining
A03020 · IHCImmunohistochemistry of paraffin-embedded rat brain using BTD antibody at dilution of 1:100 .Perform microwave antigen retrieval with 10 mM
A03020 · IHCImmunohistochemistry of paraffin-embedded human liver cancer using BTD antibody at dilution of 1:100 .Perform microwave antigen retrieval wi
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000169814-BTD/tissue/cerebral+cortex#imid_14702928
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000169814-BTD/tissue/colon#imid_14702366
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000169814-BTD/tissue/liver#imid_14702367
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000169814-BTD/tissue/kidney#imid_14702360
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for BTD IHC & IF
🧪Run breast first: myoepithelial cells should stain strongly (HPA: High in breast myoepithelial cells). Use adipose tissue as the negative comparator (HPA: Not detected in adipocytes); on the breast slide, assess neighboring non-myoepithelial cells as an internal background reference, without assuming they are BTD-negative.
Positive control tissue: Breast (Myoepithelial cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for BTD; derive a cell-line control from the positive tissue's cell type (Myoepithelial cells) and confirm it by RNA or western blot first.
Technical controls: Include no-primary (secondary-only) and host-species- and clonality-matched isotype controls, plus BTD knockout tissue or a validated immunizing-peptide block as a biological specificity control (standard IHC practice). Check endogenous peroxidase activity for chromogenic detection and endogenous biotin if using biotin-based detection; for IF, assess tissue autofluorescence (standard IHC/IF practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the fixative in the selected A03020 paraffin-section caption is unreported (selected tissue-IHC caption). That caption uses microwave retrieval in 10 mM PBS at pH 7.2 for rat brain; it does not establish retrieval dependence in breast (selected tissue-IHC caption). Neither frozen sections nor IF/ICC can be judged easier from the supplied evidence (HPA: no ICC-IF image cell lines); diffuse extracellular signal is a possible scoring complication because BTD is secreted (UniProt P43251: secreted, extracellular space).
HPA tissue IHC evidence for BTD
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — Low consistency between antibody staining and RNA expression data. Pending external verification. At least one protein variant secreted, tissue location of RNA and protein might differ and correlation is complex. 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 |
|---|---|---|---|---|
| Breast | Myoepithelial cells | High | Protein (IHC) | HPA → |
| Kidney | Cells in glomeruli | High | Protein (IHC) | HPA → |
| Liver | Hepatocytes | Medium | Protein (IHC) | HPA → |
| Parathyroid gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Stomach | Glandular 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 → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced BTD IHC Tips
Troubleshoot BTD staining in paraffin sections by checking retrieval, compartment, detection chemistry and controls before interpreting signal (UniProt P43251; HPA tissue IHC).
Which retrieval condition should I try first for BTD staining in paraffin sections?
Start with citrate buffer at pH 6.0, 95–98 °C for 20 min (page retrieval setting). A paraffin rat-brain image for catalog antibody A03020 instead used microwave retrieval in 10 mM PBS at pH 7.2, with a 1:100 primary dilution (A03020 image caption). If citrate gives weak staining, compare that documented PBS condition on adjacent sections while holding antibody dilution and detection conditions constant (A03020 image caption; standard IHC practice). Let sections cool in retrieval buffer, then compare the staining pattern and intensity with a no-primary control; stronger signal alone does not establish specificity (standard IHC practice).
How should I handle fixation when BTD staining is weak or uneven?
BTD-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative, and the supplied evidence gives no fixation comparison (A03020 image caption). Record the fixative, fixation interval and processing history for each section before changing the staining workflow (standard IHC practice). When comparable material is available, test sections with matched processing and change only 1 variable at a time, such as retrieval duration (standard IHC practice). Include a no-primary control and a consistently processed reference section in each run so differences in signal can be assessed against section handling and detection background (standard IHC practice).
Where should convincing BTD signal appear in a tissue section?
BTD is annotated as secreted into the extracellular space and has no transmembrane segment, so a strictly intracellular or membrane-only pattern needs careful validation (UniProt P43251 localisation and topology). The HPA tissue profile describes membranous staining in endothelial cells, while its tissue-IHC reliability is uncertain (HPA tissue IHC). Inspect cell borders, nearby extracellular areas and vessel structures at the same exposure, then compare them with the no-primary section (UniProt P43251 localisation; HPA tissue IHC; standard IHC practice). Record staining by compartment as well as cell type; a tissue section may contain secreted protein away from cells producing it (UniProt P43251 localisation; HPA tissue-IHC reliability note).
Could BTD processing or splice variants change what this antibody detects?
BTD has 4 annotated isoforms, but the supplied evidence does not map the catalog antibody’s epitope to any one of them (UniProt P43251 isoforms; A03020 image caption). Its signal peptide spans residues 1–21, and the annotated mature chain spans 22–523 (UniProt P43251 processing). Six annotated glycosylation sites could also affect accessibility of an epitope, although no antibody-specific effect is established here (UniProt P43251 glycosylation; A03020 image caption). If staining varies across sections, compare retrieval conditions and a reference tissue first; do not assign a missing signal to a particular isoform without epitope information (standard IHC practice; UniProt P43251 isoforms).
How can I check a BTD pattern by multiplex immunofluorescence?
Treat IF as a separate validation experiment because the supplied A03020 evidence is a paraffin-section IHC image, and HPA lists no ICC/IF image-bearing cell lines (A03020 image caption; HPA subcellular). Pair BTD with a validated marker for the expected cell population, such as endothelial cells when examining the reported vascular pattern (HPA tissue IHC; standard IF practice). Choose a spectrally separated, preferably far-red fluorophore when tissue autofluorescence affects shorter wavelengths, and inspect single-stain controls (standard IF practice). For extracellular BTD, assess staining without permeabilisation first; if testing intracellular precursor, compare gentle permeabilisation because BTD has a signal peptide and no transmembrane segment (UniProt P43251 processing and topology; standard IF practice).
What should I change when BTD staining is diffuse or vessels look uniformly brown?
Run a no-primary section through the full chromogenic workflow to locate background from tissue or detection reagents (standard IHC practice). Block endogenous peroxidase before DAB development, and compare shorter DAB development with the same reference section (standard IHC practice). If using avidin–biotin detection, check for endogenous biotin signal or compare a polymer detection system; BTD’s function involves release of biotin, which does not itself prove assay interference (UniProt P43251 function; standard IHC practice). Reduce nonspecific binding with an appropriate protein block and antibody dilution series, then retain the condition that preserves structured signal while lowering control-section staining (standard IHC practice).
How should I score BTD staining across samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the compartment and cell population before scoring, because BTD is secreted and HPA reports an uncertain endothelial staining profile (UniProt P43251 localisation; HPA tissue IHC). For cell-associated staining, record the percentage of positive cells and intensity, or calculate an H-score from intensity categories 0–3 (standard IHC practice). For extracellular staining, measure positive area or optical density per mm² of viable tissue using identical thresholds and imaging settings (standard IHC practice). Normalise each measure to the relevant viable tissue area or counted target-cell population, and report control-section background alongside the score (standard IHC practice).
How can I distinguish true BTD staining from a staining artefact?
Look for a reproducible compartment pattern across replicate sections and compare it with no-primary staining before calling a signal BTD-positive (standard IHC practice). Secreted BTD can appear outside producing cells, while HPA’s reported endothelial membrane pattern has uncertain reliability (UniProt P43251 localisation; HPA tissue IHC). Compare hepatocytes, reported at medium protein staining, with a low or undetected population within the available material; do not infer that a positive cell made the secreted protein (HPA tissue IHC; UniProt P43251 localisation). Exclude section edges, necrotic areas and signal reproduced by the no-primary control, including residual peroxidase or avidin–biotin background (standard IHC practice).
Boster reagents
Best BTD / Biotinidase IHC Antibodies
A03020 has real paraffin-section IHC images from rat brain, human liver cancer, and human prostate (A03020 image captions); listed reactivity covers human, mouse, and rat (catalog reactivity).
Real IHC data
Anti-Biotinidase BTD Antibody
Cat # A03020
The card for A03020 shows paraffin-section IHC in rat brain, with staining at 1:100 after microwave retrieval in 10 mM PBS, pH 7.2 (A03020 card caption). Additional A03020 images show paraffin-section IHC in human liver cancer and human prostate under the same stated conditions (A03020 image captions).
Which to pick: Choose A03020 for tissue IHC in paraffin sections; its listed IHC dilution is 1:100–1:200 (catalog datasheet), and the fixative is unreported in its image captions (A03020 image captions). There is no IF/ICC-validated choice in this payload: A03020 has no listed IF application or IF images (catalog applications; catalog IF images). For human, mouse, or rat samples, A03020 is the listed rabbit polyclonal option (catalog reactivity; catalog host; catalog dilution_raw), although its IHC images cover human and rat samples only (A03020 image captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P43251 (BTD_HUMAN, Biotinidase).
- Human Protein Atlas. BTD tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. BTD subcellular location (ICC-IF): Secreted.
- Human Protein Atlas. BTD antibody validation summary (1 antibodies).
- CDK9 is up-regulated and associated with prognosis in patients with papillary thyroid carcinoma. Medicine 2022 — PMC8812708.
- Extracellular Vesicle Proteome Analysis Improves Diagnosis of Recurrence in Triple-Negative Breast Cancer. Journal of extracellular vesicles 2025 — PMC12183389.
- Baitong Decoction Ameliorates DSS-Induced Colitis via Modulation of STING and JAK/STAT Pathways. ACS omega 2025 — PMC12593019.
- Liver-originated selective autophagy of BTD by alectinib underlies concurrent hepatotoxicity and dermatotoxicity. Autophagy 2026 — PMC13502023.
- PubMed PMID:7509806 — UniProt-cited evidence.
- PubMed PMID:9530634 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for BTD (Biotinidase). Expected localisation Observed endothelial membranes (HPA tissue IHC); expected extracellular space (UniProt). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A03020 at 1:100-1:200 (the product's own IHC validation image is shown). Controls (HPA): positive Breast (Myoepithelial cells); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded rat brain tissue; fixative not specified (datasheet A03020); 2. Fixation: Image fixative and duration unreported (datasheet A03020); 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-BTD, 1:100-1:200 (datasheet A03020); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific); Caveat: Secreted BTD may make staining diverge from local RNA (HPA tissue IHC); Isoform / epitope: 4 isoforms; cleavage of signal peptide 1–21 affects N-terminal epitope planning (UniProt); Regulation: Liver-enhanced RNA; staining uncertain (HPA tissue RNA + IHC). Evidence: UniProt P43251, HPA tissue IHC · Uncertain, HPA ICC-IF · Secreted, Datasheet A03020, PMC12183389. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/BTD/immunohistochemistry-ihc-guide.