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OXT / Oxytocin-neurophysin 1 proprotein · IHC design guide
Design Immunohistochemistry for OXT
Use hypothalamic magnocellular neurons as a reference for OXT staining in paraffin sections (HPA tissue IHC). This guide helps plan chromogenic IHC and interpret cytoplasmic staining in light of OXT secretion (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
OXT 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 | Cytoplasm in hypothalamic neurosecretory neurons (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining in magnocellular hypothalamic neurons (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Hypothalamus+1 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 | Secretion can separate protein staining from RNA location (HPA tissue IHC) | |
| Regulation | Regulation not annotated (UniProt) | |
| Isoform / epitope | No isoforms; cleavage separates oxytocin and neurophysin 1 (UniProt) |
Section 1
Recommended OXT IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by 2 published chromogenic OXT IHC protocols using filter-mounted tissue and mouse brain sections (PMC2637930; PMC7023993).
| Sample | Paraffin-embedded human brain tissue; fixative not specified (datasheet A01545) |
| Fixation | Image fixative and duration unreported (datasheet A01545); 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-OXT, 1:50-1:200 (datasheet A01545) |
| 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 | OXT-positive staining in neuronal cells of hypothalamus (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression mainly in magnocellular neurosecretory neurons in hypothalamus and in oocytes. No signal in the no-primary control. |
💡Decision noteFor paraffin sections, start with citrate pH 6.0 heat retrieval at 95–98 °C for 20 min (page retrieval rule).
Section 2
What Is the Expected OXT Staining Pattern?
OXT precursor is packaged in neurosecretory granules and has no transmembrane segment, so cellular staining is expected in the cytoplasm rather than at the plasma membrane (UniProt P01178). In tissue IHC, HPA reports cytoplasmic staining mainly in magnocellular neurosecretory neurons of the hypothalamus; its ovarian profile also mentions oocytes (HPA: tissue IHC). The tissue pattern has Supported reliability, with medium agreement between antibody staining and RNA data (HPA: reliability Supported).
| Distinct cytoplasmic chromogen in hypothalamic neuronal cells, with little staining in adjacent cells. | This fits the principal tissue pattern: HPA rates hypothalamic neuronal staining High and describes expression mainly in magnocellular neurosecretory neurons (HPA: tissue IHC). Granule-associated cytoplasmic staining is biologically plausible because pro-OXT is packaged into neurosecretory granules (UniProt P01178). Score the stained cells and compartment together. |
| Ovarian staining appears in follicle cells, with possible staining in oocytes. | HPA's positive-cell table rates follicle-cell staining High, while its summary also mentions oocytes (HPA: tissue IHC). Record which cell type stains rather than treating the two descriptions as identical. Interpret ovarian staining alongside morphology and a negative control; this tissue pattern alone does not establish antibody specificity. |
| Signal is predominantly nuclear or sharply outlines cell membranes. | That compartment differs from HPA's cytoplasmic tissue pattern and the vesicular or secreted localization in UniProt (HPA: tissue IHC; UniProt P01178). Review morphology and controls before calling it OXT. A membrane rim should not be justified solely by UniProt's reported interactions with vasopressin receptors (UniProt P01178). |
| Strong staining occurs in an HPA negative cell population, or chromogen is spread diffusely across the section. | For example, HPA reports OXT not detected in adipose-tissue adipocytes and caudate glial cells (HPA: tissue IHC). Such staining warrants a specificity check; cross-reactivity or endogenous detection activity are possibilities, not proven causes. Diffuse deposit without cell boundaries is also difficult to score as cellular OXT (standard IHC practice). |
| The hypothalamic neuronal positive control has no detectable signal. | This conflicts with HPA's High staining report for hypothalamic neuronal cells (HPA: tissue IHC). First check that the section contains the expected neuronal population, then assess the staining run and antibody performance (standard IHC practice). Do not infer that every hypothalamic cell must stain: HPA identifies a specific neuronal pattern. |
💡Expected OXT appearanceA convincing positive result is High, cell-associated cytoplasmic staining in hypothalamic magnocellular neurosecretory neurons (HPA: tissue IHC), consistent with vesicle-packaged pro-OXT (UniProt P01178); dominant nuclear signal, membrane outlines, or diffuse cell-independent chromogen should prompt review of controls and morphology (HPA: tissue IHC; standard IHC practice).
| Precursor processing and epitope identity | OXT is a processed precursor: UniProt annotates a signal peptide at residues 1–19 and neurophysin 1 at 32–125 (UniProt P01178). The payload does not identify the catalog antibody's epitope. Consequently, the observed stain cannot be assigned specifically to mature oxytocin, precursor, or neurophysin without epitope information. |
| Secretion and tissue location | Pro-OXT enters neurosecretory granules, and OXT products are secreted (UniProt P01178). HPA cautions that protein and RNA tissue locations can differ for a secreted protein (HPA: reliability description). Use the observed IHC cell pattern for slide interpretation; tissue RNA enrichment in brain is supporting context, not a map of every stained cell (HPA: RNA specificity). |
| Strength of IHC evidence | HPA assigns tissue staining Supported reliability and lists antibody HPA071892 as IHC Supported (HPA: tissue IHC; HPA: antibodies). HPA also notes medium staining–RNA consistency and cautions that the antibody targets protein from more than one gene (HPA: reliability description). These limits make controls and cell-level interpretation important. |
| Translation to IF/ICC | HPA's subcellular entry says secreted, but gives no main ICC/IF location or cell-line images; HPA071892 has no listed ICC status (HPA: subcellular; HPA: antibodies). The IHC tissue pattern therefore does not establish an IF/ICC appearance or validation. Evaluate IF/ICC on its own guide page using that application's evidence. |
| Situation | Likely cause | Next action |
|---|---|---|
| The expected hypothalamic neurons are negative. | The relevant neuronal population may be absent from the section, or the staining run may have failed; HPA reports High neuronal staining in hypothalamus (HPA: tissue IHC). | Confirm tissue anatomy and inspect a known-positive section processed in the same run. Then review the antibody and detection controls and the validated IHC-P workflow (standard IHC practice). |
| Many unrelated cell types show uniform brown signal. | Broad signal is inconsistent with HPA's mainly hypothalamic neuronal cytoplasmic pattern; nonspecific binding or endogenous detection activity may contribute (HPA: tissue IHC; standard IHC practice). | Compare a negative detection control and inspect whether signal follows cells or tissue deposits. Review blocking and detection conditions within the established chromogenic IHC workflow (standard IHC practice). |
| Nuclei or membrane rims dominate the stain. | The compartment conflicts with HPA's cytoplasmic tissue pattern and UniProt's secretory-vesicle localization; OXT has no annotated transmembrane segment (HPA: tissue IHC; UniProt P01178). | Check the counterstain and cell boundaries, then compare positive and negative controls. Withhold an OXT-positive call until a plausible cytoplasmic cellular pattern is demonstrated. |
| Adipose-tissue adipocytes or caudate glia stain strongly. | HPA reports OXT not detected in those cell populations; the signal may reflect cross-reactivity or a detection artifact, although the image alone cannot determine which (HPA: tissue IHC). | Verify cell identity, compare the same run's hypothalamic positive control, and inspect a negative detection control before assigning the unexpected signal to OXT (standard IHC practice). |
| Ovarian results seem inconsistent between cell annotations. | HPA's positive table names follicle cells, while its profile also mentions oocytes (HPA: tissue IHC). These are distinct cell descriptions and should not be merged when scoring. | Annotate follicle cells and oocytes separately on the slide. Report the compartment and intensity for each, and qualify any conclusion that depends on which population is stained. |
| Can the IHC pattern be used as an IF/ICC positive-control specification? | HPA provides no ICC/IF images or main subcellular location for OXT, and lists no ICC status for HPA071892 (HPA: subcellular; HPA: antibodies). | Use the separate IF/ICC guide to define that application's controls and interpretation. Treat the IHC cytoplasmic pattern as biological context, not as IF/ICC validation. |
Experiment evidence
IHC & IF images showing OXT staining
A01545 · IHCImmunohistochemistry (IHC) analyzes of Neurophysin I (K40) pAb in paraffin-embedded human brain tissue.
HPA · HypothalamusHuman Protein Atlas IHC, Hypothalamus. Source: https://www.proteinatlas.org/ENSG00000101405-OXT/tissue/hypothalamus#imid_997
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000101405-OXT/tissue/cerebral+cortex#imid_20395813
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000101405-OXT/tissue/colon#imid_20398563
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000101405-OXT/tissue/liver#imid_20398556
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for OXT IHC & IF
🧪Run hypothalamus first and look for staining in neuronal cells (HPA: High in hypothalamic neuronal cells). Run adipose tissue as the negative tissue, where adipocytes should remain unstained (HPA: Not detected in adipocytes); on the hypothalamus slide, assess background in adjacent cells outside the neuronal staining pattern.
Positive control tissue: Hypothalamus (Neuronal 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 OXT; derive a cell-line control from the positive tissue's cell type (Neuronal cells) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control; an irrelevant immunoglobulin matched to the primary antibody’s host species, isotype, and clonality; and a biological negative such as OXT knockout tissue or peptide blocking when an appropriate peptide is available. For chromogenic IHC, quench endogenous peroxidase and, if using biotin-based detection, block endogenous biotin; for IF, check tissue autofluorescence with the no-primary control.
⚠️Feasibility: Paraffin-section staining has been shown in human brain with the catalog antibody, but the caption does not report a fixative (A01545 tissue-IHC caption). A target-specific fixation window and antigen-retrieval dependence are unreported in the supplied evidence, so retrieval conditions need empirical optimization. The supplied evidence does not establish whether frozen sections or IF are easier; neuronal lipofuscin can cause autofluorescence in IF, and HPA lists no ICC-IF image cell lines for OXT (HPA subcellular record).
HPA tissue IHC evidence for OXT
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — Medium consistency between antibody staining and RNA expression data. Caution, targets protein from more than one gene. Secreted protein, tissue location of RNA and protein is expected to differ. External characterization data supports antibody staining.). 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 |
|---|---|---|---|---|
| Hypothalamus | Neuronal cells | High | Protein (IHC) | HPA → |
| Ovary | Follicle cells | High | 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 | Lymphoid tissue | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced OXT IHC Tips
Troubleshoot paraffin-section chromogenic IHC for OXT by checking retrieval, cellular distribution, processing and controls before interpreting staining intensity.
How should I retrieve OXT antigen when paraffin sections stain weakly?
For paraffin IHC, start with citrate buffer at pH 6.0, 95–98 °C for 20 min (page retrieval setting). Keep section thickness, heating and cooling consistent across the test and control slides so differences in staining can be attributed to the retrieval comparison (standard IHC practice). If signal remains weak, compare a modestly longer citrate retrieval with the starting condition while checking for tissue damage and increased background (standard IHC practice). Evaluate cytoplasmic staining in hypothalamic neuronal cells as an expected pattern, but confirm specificity independently because the HPA antibody may recognize proteins from more than one gene (HPA: tissue IHC profile and reliability description).
Could fixation explain weak or uneven OXT staining?
The A01545 image documents staining in paraffin-embedded human brain, but its caption does not report the fixative or fixation duration (A01545 tissue-IHC caption). OXT-specific fixation sensitivity is therefore unknown; neither the HPA staining pattern nor the protein’s secretory-vesicle location establishes a preferred fixation condition (HPA: tissue IHC profile; UniProt P01178 subcellular annotation). Record the actual fixative, fixation interval and processing history for each specimen, then compare sections processed alike before changing retrieval conditions (standard IHC practice). If staining varies between blocks, assess morphology and matched control sections alongside the signal, because processing differences can affect antigen accessibility and tissue preservation (standard IHC practice).
Where should convincing OXT staining appear in paraffin IHC?
Expect predominantly cytoplasmic staining in magnocellular neurosecretory neurons of the hypothalamus, the principal neuronal pattern described for this target (HPA: tissue IHC profile). Pro-OXT is packaged into neurosecretory granules and has no transmembrane segment, so discrete cytoplasmic or process-associated signal is more plausible than a continuous plasma-membrane outline (UniProt P01178 subcellular annotation and topology). Secreted material can appear away from its site of synthesis, so tissue staining need not mirror local RNA expression (HPA: reliability description). Compare the stained cells with section anatomy and a matched negative control; diffuse nuclear staining or uniform staining across unrelated cell types warrants investigation (standard IHC practice).
Can this stain distinguish mature oxytocin from its precursor or neurophysin 1?
Do not assign the stained molecule solely from the OXT gene name: its precursor is processed into oxytocin and neurophysin 1 (UniProt P01178 function and processing annotations). The A01545 caption calls the reagent a neurophysin I antibody, but supplies no mapped epitope, so its reactivity with intact precursor versus processed products cannot be resolved from that caption (A01545 tissue-IHC caption). UniProt lists 0 isoforms and 0 glycosylation sites; those annotations do not establish which processed species survives paraffin preparation (UniProt P01178 isoform and glycosylation annotations). Check the catalog antibody’s epitope documentation and use an independent specificity control before labeling a positive cell as containing mature oxytocin (standard IHC practice).
How can I examine OXT colocalisation by IF without overreading this IHC result?
Treat IF as a separate assay: the A01545 evidence is a paraffin tissue-IHC image, and the supplied HPA subcellular record has no ICC/IF image (A01545 tissue-IHC caption; HPA: subcellular record). For multiplexing, pair the OXT antibody with a validated marker of the expected magnocellular neuronal population and include single-stain controls to assess channel bleed-through (HPA: tissue IHC profile; standard IF practice). Choose fluorophores after examining unstained tissue autofluorescence, favoring a clean spectral channel for the weaker signal (standard IF practice). Because pro-OXT is packaged inside secretory vesicles and lacks a transmembrane segment, optimize permeabilisation for access to an intracellular epitope while checking that cell structure remains intact (UniProt P01178 subcellular annotation and topology; standard IF practice).
What should I adjust when OXT IHC shows widespread brown background?
Inspect the no-primary control and unstained section first to separate detection-system staining from tissue pigment or intrinsic color (standard chromogenic IHC practice). Apply an endogenous-peroxidase block before HRP/DAB detection, then check whether residual brown signal persists without primary antibody; these are general workflow checks, not OXT-specific validation (standard chromogenic IHC practice). If background depends on primary antibody, titrate its concentration and incubation time and assess blocking and wash steps using matched sections (standard IHC practice). Extensive staining across cell types is difficult to reconcile with the reported predominance in hypothalamic magnocellular neurons, although the HPA antibody also carries a cross-gene caution (HPA: tissue IHC profile and reliability description).
How should I score OXT-positive cells across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the anatomical region and cell population before scoring; hypothalamic magnocellular neuronal staining is the reported reference pattern (HPA: tissue IHC profile). Report the percentage of positive eligible neurons and an intensity-based H-score on a 0–300 scale, or count positive cells per mm² when cell density is the question (standard IHC quantification practice). Normalize counts to the number of eligible neurons or measured region area, and keep section thickness, staining run, imaging settings and positivity threshold consistent (standard IHC quantification practice). Score cytoplasmic signal separately from extracellular or ambiguous deposits because OXT is secreted and protein location need not match the site of RNA expression (UniProt P01178 subcellular annotation; HPA: reliability description).
How can I distinguish credible OXT staining from artefact?
A credible result follows the reported cytoplasmic pattern in hypothalamic magnocellular neurons and is reproducible in matched sections (HPA: tissue IHC profile; standard IHC practice). Flag strong nuclear or continuous membrane-outline staining for review, since pro-OXT is packaged in secretory vesicles and has no transmembrane segment (UniProt P01178 subcellular annotation and topology). Compare suspicious edge staining, damaged or necrotic areas, and brown deposits with the no-primary control and an endogenous-peroxidase-blocked section (standard chromogenic IHC practice). A positive stain alone cannot establish OXT specificity: the HPA reliability note cautions that its antibody can recognize proteins from more than one gene, and secretion can separate protein from local RNA (HPA: reliability description).
Boster reagents
Best OXT / Oxytocin-neurophysin 1 proprotein IHC Antibodies
A01545 has IHC data from paraffin-embedded human brain tissue (A01545 IHC image caption). Listed reactivity covers Human, Mouse, and Rat (catalog: reactivity); no IF image is supplied (catalog: IF image alts).
Real IHC data
Anti-Neurophysin I (K40) OXT Antibody
Cat # A01545
A01545 is listed for IHC in Human, Mouse, and Rat (catalog: applications, reactivity). Its IHC image shows paraffin-embedded human brain tissue (A01545 IHC image caption).
Which to pick: Choose A01545 for paraffin-section tissue IHC: its own image documents human brain tissue, but does not report the fixative (A01545 IHC image caption). The rabbit pAb is listed as reactive with Mouse and Rat, although its supplied IHC image shows only human tissue (catalog: host, reactivity; A01545 IHC image caption). No SKU has listed IF/ICC validation or an IF image, so the payload does not support an IF/ICC pick (catalog: applications, IF image alts).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P01178 (NEU1_HUMAN, Oxytocin-neurophysin 1 proprotein).
- Human Protein Atlas. OXT tissue IHC expression (reliability: Supported).
- Human Protein Atlas. OXT subcellular location (ICC-IF): Secreted.
- Human Protein Atlas. OXT antibody validation summary (1 antibodies).
- Effects of ciliary neurotrophic factor and leukemia inhibiting factor on oxytocin and vasopressin magnocellular neuron survival in rat and mouse hypothalamic organotypic cultures. Journal of neuroscience methods 2009 — PMC2637930.
- Oxytocin receptor gene loss influences expression of the oxytocin gene in C57BL/6J mice in a sex- and age-dependent manner. Journal of neuroendocrinology 2020 — PMC7023993.
- Expression of Oxytocin/Neurophysin I and Oxytocinase in the Equine Conceptus from Day 8 to Day 21 Post-Ovulation. Animals : an open access journal from MDPI 2022 — PMC8996865.
- Oxytocin activity in the paraventricular and supramammillary nuclei of the hypothalamus is essential for social recognition memory in rats. Molecular psychiatry 2024 — PMC11116117.
- PubMed PMID:3768139 — UniProt-cited evidence.
- PubMed PMID:2991279 — UniProt-cited evidence.
- PubMed PMID:11780052 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for OXT (Oxytocin-neurophysin 1 proprotein). Expected localisation Cytoplasm in hypothalamic neurosecretory neurons (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A01545 at 1:50-1:200 (the product's own IHC validation image is shown). Controls (HPA): positive Hypothalamus (Neuronal cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human brain tissue; fixative not specified (datasheet A01545); 2. Fixation: Image fixative and duration unreported (datasheet A01545); 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-OXT, 1:50-1:200 (datasheet A01545); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Secretion can separate protein staining from RNA location (HPA tissue IHC); Isoform / epitope: No isoforms; cleavage separates oxytocin and neurophysin 1 (UniProt); Regulation: Regulation not annotated (UniProt). Evidence: UniProt P01178, HPA tissue IHC · Supported, HPA ICC-IF · Secreted, Datasheet A01545, PMC2637930, PMC7023993. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/OXT/immunohistochemistry-ihc-guide.