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OAS2 / 2'-5'-oligoadenylate synthase 2 · IHC design guide
Design Immunohistochemistry for OAS2
Plan OAS2 staining in paraffin sections using the reported nuclear and cytoplasmic tissue pattern (HPA tissue IHC). The guide covers fixation consistency, antibody dilution of 1:100–1:300 (datasheet), and interpretation in light of interferon-induced expression (UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
OAS2 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 | Nuclear and cytoplasmic tissue staining (HPA tissue IHC) | |
| Staining pattern | Nuclear and 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 | Appendix+4 more · see all | |
| Negative control | None in HPA (detected in all 45 tissues); use no-primary + isotype controls |
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 | Antibody staining and RNA show medium consistency (HPA tissue IHC) | |
| Regulation | Interferon-induced expression (UniProt) | |
| Isoform / epitope | Three isoforms; epitope coverage needs validation (UniProt) |
Section 1
Recommended OAS2 IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by three published OAS2 IHC workflows (PMC10187978; PMC9510761; PMC11483074).
| Sample | Paraffin-embedded human uterus tissue; fixative not specified (datasheet A01878) |
| Fixation | Image fixative and duration unreported (datasheet A01878); 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-OAS2, 1:100-1:300 (datasheet A01878) |
| 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 | OAS2-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: General nuclear and cytoplasmic expression. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 retrieval at 95–98 °C for 20 min (page retrieval rule); use each paper’s conditions when reproducing its workflow.
Section 2
What Is the Expected OAS2 Staining Pattern?
In paraffin-section IHC, expect OAS2 staining in the cytoplasm, often around the nucleus, with possible nuclear staining (UniProt P29728 localisation; HPA: general nuclear and cytoplasmic expression). High-staining examples include appendix glandular cells, bone-marrow hematopoietic cells and colon endothelial cells (HPA tissue IHC). OAS2 has no transmembrane segment (UniProt P29728 topology). HPA rates its tissue IHC profile Approved, with medium consistency between staining and RNA expression (HPA tissue IHC).
| Cell-associated cytoplasmic staining, sometimes perinuclear, in the expected cells; nuclear staining may accompany it. | This fits the reported cytoplasmic and perinuclear localisation (UniProt P29728 localisation) and the general nuclear and cytoplasmic tissue profile (HPA tissue IHC). Score the cell type and compartment together; the tissue profile does not require every positive cell to show identical nuclear intensity. |
| Staining is confined to luminal material or extracellular space, with no convincing signal inside cells. | That distribution does not match the reported intracellular localisation (UniProt P29728 localisation; HPA tissue IHC). Treat it as a possible artefact and review morphology, reagent controls and whether the signal persists where cells are intact. Do not classify nuclear staining alone as a wrong compartment: HPA reports nuclear expression (HPA tissue IHC). |
| Strong signal appears mainly in an unexpected cell population, while the expected cells are weak. | Compare the stained cells with the specified HPA cell types, rather than judging the whole tissue as positive (HPA tissue IHC). A mismatch warrants checks for antibody cross-reactivity or detection-system activity; HPA's Approved rating has only medium staining–RNA consistency and does not validate every cell on a new slide (HPA tissue IHC). |
| Pale, widespread colour obscures cell boundaries and the intended intracellular pattern. | This is difficult to score as OAS2. In chromogenic IHC, nonspecific antibody binding, incomplete blocking, residual detection activity or overly concentrated reagents can create diffuse background (general IHC practice). Reassess the pattern only after the control and background signal allow individual cells to be identified. |
| No staining is visible in a selected HPA high-staining cell population. | A technical false negative is possible, but an HPA High entry is an observed cell-specific pattern, not a guarantee for every section or antibody (HPA tissue IHC). Confirm that the chosen cells are present, then review the catalog antibody's IHC-P instructions, detection controls and section quality before interpreting absence. |
💡Expected OAS2 appearanceA persuasive positive is discernible intracellular staining, chiefly cytoplasmic with possible perinuclear or nuclear signal, in a selected HPA High cell population; lumen-only colour or diffuse, cell-independent deposit is suspect (UniProt P29728 localisation; HPA tissue IHC).
| Cell choice and scoring | HPA lists High staining in appendix and duodenum glandular cells, bone-marrow hematopoietic cells, caudate glia, cerebellar granular-layer cells, cerebral-cortex and colon endothelium, and cervical squamous epithelium (HPA tissue IHC). Select and score the named cells within the section; neighbouring cells are not interchangeable positive controls. |
| Evidence strength and antibody choice | The tissue profile is Approved with medium staining–RNA consistency (HPA tissue IHC). CAB024984 has IHC Approved status, while HPA003320 has ICC Approved status with no IHC status supplied (HPA antibody records). Those labels support application-specific interpretation; they do not establish identical patterns across antibodies. |
| Intracellular distribution | UniProt places OAS2 in the cytoplasm, perinuclear region and Golgi apparatus membrane and reports no transmembrane segment (UniProt P29728 localisation/topology). HPA describes general nuclear and cytoplasmic tissue staining (HPA tissue IHC). Record those observations separately if nuclear and cytoplasmic scores differ. |
| Isoforms and induction | UniProt lists three isoforms—p71, p69 and isoform 3—and describes OAS2 as interferon-induced (UniProt P29728). The supplied records do not map this antibody's epitope to an isoform or specify an induction state for the HPA sections. Avoid attributing a staining difference to either mechanism without separate evidence. |
| Can the ICC-IF result set the IHC pattern? | HPA reports an approved centrosome location in ICC-IF images from SK-MEL-30 (HPA subcellular ICC-IF). Treat this as an application-specific observation: it does not establish that centrosomes must resolve in chromogenic paraffin-section IHC, whose tissue profile is general nuclear and cytoplasmic (HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| Expected cells are unstained, but the section has usable morphology. | The named positive cells may be absent from the sampled area, or the IHC procedure may have lost detectable signal; HPA High is cell-specific (HPA tissue IHC). | Verify the cell population on the counterstain and compare a documented positive section. Review the catalog antibody's IHC-P instructions and detection controls before changing conditions (general IHC practice). |
| Both tissue and negative-control areas show broad chromogenic colour. | Background may arise from nonspecific binding or endogenous detection activity, depending on the chromogen system (general IHC practice). | Inspect reagent-omission controls, blocking and wash steps; address endogenous peroxidase if using an HRP system (general IHC practice). Do not assign the broad colour to OAS2. |
| Colour is concentrated in lumens, debris or torn section edges. | Trapped reagent or precipitate can mimic a positive signal (general IHC practice); these sites do not match the reported intracellular distribution (UniProt P29728 localisation). | Compare intact cells away from damaged areas and examine a detection control. Score only interpretable cell-associated staining (general IHC practice). |
| A different cell type dominates the stain in a chosen positive tissue. | The selected region may not contain the HPA-listed positive cells, or the signal may reflect cross-reactivity or background (HPA tissue IHC; general IHC practice). | Identify the named cell population on the counterstain, then compare its signal with a reagent control and a second suitable section. Record the cell-type mismatch rather than calling the tissue uniformly positive. |
| Nuclear signal seems stronger than cytoplasmic signal. | HPA reports general nuclear and cytoplasmic expression, while UniProt also reports cytoplasmic and perinuclear localisation (HPA tissue IHC; UniProt P29728 localisation). | Score nuclear and cytoplasmic compartments separately and check whether the signal stays within intact cells. Nuclear colour alone is insufficient grounds to reject the stain (HPA tissue IHC). |
| A centrosomal punctum is absent from paraffin-section IHC. | The approved centrosome finding comes from ICC-IF, whereas the supplied tissue IHC profile describes general nuclear and cytoplasmic expression (HPA subcellular ICC-IF; HPA tissue IHC). | Judge the paraffin section against its cell-type and intracellular tissue pattern. Do not require a visible centrosomal punctum for an IHC positive call (HPA tissue IHC). |
Experiment evidence
IHC & IF images showing OAS2 staining
A01878 · IHCImmunohistochemical analysis of paraffin-embedded human-uterus, antibody was diluted at 1:100
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000111335-OAS2/tissue/cerebral+cortex#imid_6664664
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000111335-OAS2/tissue/colon#imid_6664582
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000111335-OAS2/tissue/liver#imid_6664599
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000111335-OAS2/tissue/kidney#imid_6664584
HPA · ICC-IF SK-MEL-30Human Protein Atlas immunofluorescence, SK-MEL-30, antibody HPA003320; green = OAS2, blue = nucleus, red = microtubules.
HPA · ICC-IF SK-MEL-30Human Protein Atlas immunofluorescence, SK-MEL-30, antibody HPA003320; green = OAS2, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for OAS2 IHC & IF
🧪Run appendix first and expect staining in glandular cells (HPA: Appendix glandular cells, High); cells judged negative on that slide should retain counterstain without specific chromogen, but HPA identifies no validated negative cell population there (HPA: Appendix row). HPA detects OAS2 in all 45 scored tissues, so there is no supported negative tissue; use no-primary and isotype controls to establish background (HPA: no negative rows; OAS2 detected in all 45 scored tissues).
Positive control tissue: Appendix (Glandular cells, HPA High)
Negative control tissue: None in HPA: OAS2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show OAS2 in SK-MEL-30, with annotated localisation: Centrosome (approved) (HPA subcellular).
Technical controls: Run a no-primary, secondary-only control and an irrelevant IgG control matched to the primary antibody’s host species and isotype; use OAS2-knockout material or antigen peptide competition, when available, to assess specificity (standard IHC practice). In appendix, quench endogenous peroxidase and check for endogenous biotin if using avidin–biotin detection, particularly around leukocytes (standard IHC practice).
⚠️Feasibility: A target-specific fixation window and antigen-retrieval requirement are unreported; the A01878 paraffin-section caption gives 1:100 for uterus but does not state a fixative (selected A01878 caption). The evidence does not establish whether frozen sections or IF are easier for OAS2, although ICC-IF images are available for SK-MEL-30 (HPA subcellular). Endogenous peroxidase in appendix leukocytes can complicate chromogenic interpretation (standard IHC practice).
HPA tissue IHC evidence for OAS2
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — 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 |
|---|---|---|---|---|
| Appendix | Glandular cells | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | High | Protein (IHC) | HPA → |
| Cerebral cortex | Endothelial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| None in HPA: OAS2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead. | ||||
Section 3
Advanced OAS2 IHC Tips
Troubleshoot OAS2 staining in paraffin section chromogenic IHC using the catalog antibody’s image, the page retrieval setting, and independent localisation evidence.
What retrieval conditions should I try first for OAS2 in paraffin sections?
Start with citrate buffer at pH 6.0, heated to 95–98 °C for 20 min (page retrieval specification). Allow slides to cool in the buffer before washing, and keep section thickness and heating conditions consistent across the comparison set (standard IHC practice). If staining is weak, test a more alkaline retrieval buffer on adjacent sections while retaining the citrate condition as the reference (standard IHC practice). Score signal separately from tissue damage and background, since stronger colour alone does not establish specific OAS2 detection (standard IHC practice). The catalog image documents staining of paraffin embedded human uterus at 1:100, but its caption does not report retrieval conditions (A01878 caption).
How should I handle fixation when OAS2 staining is weak or uneven?
OAS2 specific sensitivity to fixation is unknown from the supplied evidence; the catalog caption identifies paraffin embedded human uterus but does not state its fixative (A01878 caption). Record each specimen’s fixative, fixation duration, and processing history before comparing staining intensity (standard IHC practice). When possible, compare sections processed together and hold retrieval, antibody dilution, and detection time constant (standard IHC practice). If staining varies between specimens, use an independently supported positive tissue on the same run to check assay performance; appendix glandular cells are reported as high staining (HPA: High in appendix glandular cells). Do not assign the difference to fixation without a controlled comparison.
Which OAS2 staining compartments should I expect in chromogenic IHC?
Examine cytoplasmic and perinuclear staining first, while recording any Golgi region accentuation (UniProt P29728 localisation). The protein has no annotated transmembrane segment, so an isolated crisp cell surface outline warrants scrutiny (UniProt P29728 topology). HPA describes general nuclear and cytoplasmic tissue staining, while its approved subcellular IF location is the centrosome; these observations come from different assays (HPA tissue IHC profile; HPA subcellular). Score nuclear and cytoplasmic compartments separately rather than treating every brown structure as equivalent (standard IHC practice). Check whether staining follows intact cells and expected anatomy across the section before interpreting a punctate or nuclear pattern as OAS2 (standard IHC practice).
Can this IHC stain distinguish OAS2 isoforms or epitope accessibility?
Do not assign a chromogenic staining pattern to p71, p69, or isoform 3 without an isoform specific epitope map or validation (UniProt P29728 isoforms). The supplied catalog image gives a 1:100 dilution in paraffin embedded human uterus but no epitope or isoform specificity (A01878 caption). Compare adjacent sections under the same retrieval and detection conditions when assessing whether an alternative retrieval changes accessibility (standard IHC practice). OAS2 has no annotated transmembrane segment, and its listed modified residues include N6 acetyllysine at position 378; neither fact establishes how this antibody binds processed tissue (UniProt P29728 topology and modified residues). Report the result as OAS2 immunoreactivity unless additional specificity evidence supports a narrower claim.
How can I use IF to check an ambiguous OAS2 IHC pattern?
Use IF as a separate localisation check, selecting a marker for the cell population being assessed; HPA reports high OAS2 tissue staining in appendix glandular cells and bone marrow hematopoietic cells (HPA tissue IHC). Choose fluorophores after inspecting an unstained section, since tissue autofluorescence can obscure weak signal (standard IF practice). Permeabilise to access a cytoplasmic or perinuclear epitope, then optimise detergent exposure against morphology and background; OAS2 has no annotated transmembrane segment (UniProt P29728 localisation and topology; standard IF practice). HPA reports an approved centrosome location from ICC/IF in SK-MEL-30 cells, which provides a pattern to examine rather than a required appearance in every tissue (HPA subcellular).
How do I separate OAS2 signal from chromogenic background?
Inspect a no primary antibody control for detection reagent deposits and endogenous peroxidase signal (standard chromogenic IHC practice). Include a peroxidase blocking step before chromogen development, and compare the control with the test slide using the same DAB development time (standard chromogenic IHC practice). If diffuse brown colour persists, review antibody concentration, blocking, washes, and chromogen exposure one variable at a time (standard IHC practice). The catalog image used a 1:100 antibody dilution in paraffin embedded human uterus; treat that as an image condition, not a proven optimum for every specimen (A01878 caption). Retain compartment and cell morphology when judging whether reduced background also preserves plausible OAS2 staining (UniProt P29728 localisation; standard IHC practice).
What should I quantify when comparing OAS2 IHC across samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, then use percent positive cells or an H-score for staining intensity within that population (standard IHC scoring practice). For spatial comparisons, report positive cell density per mm² of viable tissue and exclude folds, section edges, and necrotic areas (standard IHC scoring practice). Normalise counts to the number of eligible cells or viable tissue area, and apply identical colour thresholds and acquisition settings across slides (standard IHC scoring practice). Record nuclear and cytoplasmic scores separately because HPA describes both in tissue IHC (HPA tissue IHC profile). Report cell composition alongside the score, since HPA lists high staining in several distinct cell populations (HPA tissue IHC).
When is an apparent OAS2 positive cell likely to be an artefact?
Treat signal in intact cytoplasm or the perinuclear region as more consistent with the UniProt localisation record than a cell surface outline (UniProt P29728 localisation and topology). Compare the stained cell type with the local morphology and an appropriate positive control; HPA reports high staining in appendix glandular cells, among other populations (HPA tissue IHC). Distrust colour confined to section edges, folds, or necrotic material, and check no primary controls for endogenous enzyme activity (standard chromogenic IHC practice). Nuclear staining alone needs cautious interpretation because HPA reports general nuclear and cytoplasmic tissue staining, while UniProt lists cytoplasmic locations (HPA tissue IHC profile; UniProt P29728 localisation). HPA rates its tissue evidence Approved with medium RNA and staining consistency, so document the observed compartment and controls with the conclusion (HPA tissue IHC reliability).
Boster reagents
Best OAS2 / 2'-5'-oligoadenylate synthase 2 IHC Antibodies
A01878 is listed for IHC and IF in human, mouse and rat (catalog: applications; reactivity). Its IHC image shows a paraffin-embedded human uterus section (A01878 IHC image caption).
Real IHC data
Anti-OAS2 Antibody
Cat # A01878
A01878 has an IHC image of paraffin-embedded human uterus at 1:100 (A01878 IHC image caption). IF is listed, but no IF image is supplied (catalog: applications; IF image alts).
Which to pick: Choose A01878 for paraffin-section IHC: its image shows human uterus at 1:100, within the listed 1:100–1:300 IHC range (A01878 IHC image caption; catalog: IHC dilution). For IF, A01878 is listed at 1:50; ICC validation and an IF image are unreported (catalog: applications; IF dilution; IF image alts). A01878 also lists mouse and rat reactivity, though its IHC image shows human tissue; the antibody is rabbit-hosted, clonality is unreported, and the image caption does not specify a fixative (catalog: reactivity; host; clone; A01878 IHC image caption).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P29728 (OAS2_HUMAN, 2'-5'-oligoadenylate synthase 2).
- Human Protein Atlas. OAS2 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. OAS2 subcellular location (ICC-IF): Localized to the centrosome..
- Human Protein Atlas. OAS2 antibody validation summary (2 antibodies).
- The proteomic landscape of glioblastoma recurrence reveals novel and targetable immunoregulatory drivers. Acta neuropathologica 2022 — PMC10187978.
- Values of OAS gene family in the expression signature, immune cell infiltration and prognosis of human bladder cancer. BMC cancer 2022 — PMC9510761.
- Identification of NET formation and the renoprotective effect of degraded NETs in lupus nephritis. American journal of physiology. Renal physiology 2024 — PMC11483074.
- Biological Characterization and Clinical Value of OAS Gene Family in Pancreatic Cancer. Frontiers in oncology 2022 — PMC9205247.
- PubMed PMID:1577824 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:16541075 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for OAS2 (2'-5'-oligoadenylate synthase 2). Expected localisation Nuclear and cytoplasmic tissue staining (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A01878 at 1:100-1:300 (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative None in HPA (detected in all 45 tissues); use no-primary + isotype controls. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Paraffin-embedded human uterus tissue; fixative not specified (datasheet A01878); 2. Fixation: Image fixative and duration unreported (datasheet A01878); 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-OAS2, 1:100-1:300 (datasheet A01878); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific); Caveat: Antibody staining and RNA show medium consistency (HPA tissue IHC); Isoform / epitope: Three isoforms; epitope coverage needs validation (UniProt); Regulation: Interferon-induced expression (UniProt). Evidence: UniProt P29728, HPA tissue IHC · Approved, HPA ICC-IF · centrosome., Datasheet A01878, PMC10187978, PMC9510761. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/OAS2/immunohistochemistry-ihc-guide.