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SRR / Serine racemase · IHC design guide
Design Immunohistochemistry for SRR
Plan SRR chromogenic IHC in paraffin sections using 2–5 μg/ml catalog antibody (datasheet A02660-2). Assess cytoplasmic and nuclear staining with HPA-listed positive and undetected cell types as references (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SRR 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 and nuclear tissue staining (HPA tissue IHC) | |
| Staining pattern | Purkinje cells stain; cytoplasmic/nuclear pattern across tissues (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A02660-2) | |
| Positive control | Adipose tissue+4 more · see all | |
| Negative control | Oral mucosa+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 | Cell-type variation: oral squamous cells are undetected (HPA tissue IHC) | |
| Regulation | Higher in schizophrenia DLPFC (UniProt) | |
| Isoform / epitope | One 1–340 chain; no isoforms or signal peptide annotated (UniProt) |
Section 1
Recommended SRR IHC & IF Protocols
The catalog antibody uses EDTA pH 8.0 heat retrieval (datasheet: A02660-2). The published brain IHC protocols below use pH 6.0 retrieval (PMC10090982; PMC11337596).
| Sample | Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet A02660-2) |
| Fixation | Image fixative and duration unreported (datasheet A02660-2); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A02660-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A02660-2) |
| Primary antibody | Rabbit anti-SRR, 2-5 μg/ml (datasheet A02660-2) |
| Primary incubation | Overnight at 4 °C (datasheet A02660-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A02660-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SRR-positive staining in adipocytes of adipose tissue (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic and nuclear expression in several tissues. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet: A02660-2); evaluate pH 6.0 retrieval when adapting either published brain protocol (PMC10090982; PMC11337596).
Section 2
What Is the Expected SRR Staining Pattern?
In paraffin IHC, expect cytoplasmic and nuclear SRR staining in selected cells, including cerebellar Purkinje cells, caudate glia and cerebral cortical neurons (HPA tissue IHC: Medium; Approved, pending external verification). SRR has no transmembrane segment (UniProt Q9GZT4 topology). HPA’s separate ICC-IF record reports vesicles (HPA subcellular: approved); that finding does not define the paraffin IHC pattern.
| Purkinje cells, caudate glia or cortical neurons show discernible cytoplasmic and nuclear staining. | This fits HPA’s reported Medium staining in those cell populations and its broader cytoplasmic and nuclear IHC profile (HPA tissue IHC: Approved, pending external verification). Judge the identified cells against nearby tissue background; Medium is an HPA category, not a required numeric intensity. |
| A sharp cell-surface rim dominates while cytoplasmic and nuclear staining is absent. | A membrane-dominant result departs from the reported IHC profile (HPA tissue IHC: cytoplasmic and nuclear). SRR lacks a transmembrane segment (UniProt Q9GZT4 topology). Treat the rim as suspect, then compare control sections and antibody performance before assigning it to SRR. |
| Strong staining appears in oral squamous epithelium, ovarian stroma or smooth muscle cells. | HPA lists these specific cell populations as Not detected (HPA tissue IHC). Unexpected staining raises possible cross-reactivity or detection background; it does not, by itself, prove either. Confirm the cell identity and examine a detection-only control before interpreting a new biological pattern. |
| Brown signal spreads evenly across unrelated cells, extracellular areas and the section edge. | This distribution is difficult to reconcile with HPA’s cell-specific observations (HPA tissue IHC). Diffuse deposit can arise from nonspecific binding or chromogenic detection background (general IHC practice). Check background controls before scoring cytoplasmic or nuclear signal. |
| No staining is visible in a well-preserved cerebellar section containing identifiable Purkinje cells. | Purkinje cells are a reported Medium-positive population (HPA tissue IHC), so a blank result warrants a technical check. It is not definitive evidence that the sample lacks SRR: HPA rates its tissue profile Approved while noting that external verification is pending (HPA tissue IHC). |
💡Expected SRR appearanceCall a result positive when identified Purkinje cells, caudate glia or cortical neurons show discernible cytoplasmic and nuclear staining around HPA’s Medium category; a dominant membrane rim or equally strong signal in HPA Not detected cell populations is suspect (HPA tissue IHC; UniProt Q9GZT4 topology).
| Tissue and cell selection | Choose an identifiable reported positive population when evaluating the stain: Purkinje cells, caudate glia and cortical neurons are Medium (HPA tissue IHC). Oral squamous epithelium, ovarian stroma and smooth muscle cells are listed as Not detected (HPA tissue IHC); these labels apply to those cells, not every cell in each organ. |
| Assay-specific localisation | Paraffin tissue IHC is reported as cytoplasmic and nuclear, whereas ICC-IF localisation is approved for vesicles (HPA tissue IHC; HPA subcellular). Keep the readouts distinct when interpreting a chromogenic section. UniProt gives no subcellular annotation for SRR (UniProt Q9GZT4). |
| Antibody validation | The supplied antibody list assigns IHC Approved to CAB015343 and ICC Approved to HPA007529 (HPA antibodies). Those statuses are application-specific; ICC approval does not establish paraffin IHC performance for that antibody. The overall tissue IHC profile remains pending external verification (HPA tissue IHC). |
| Topology and processing | SRR has no transmembrane segment, signal peptide or propeptide; the annotated chain spans residues 1–340 (UniProt Q9GZT4 topology and processing). These facts help flag a membrane-only interpretation, but they do not identify the catalog antibody’s epitope or predict how retrieval will affect staining. |
| Retrieval and chromogenic detection | Use the selected antibody’s documented paraffin IHC conditions as the starting point, and include controls for background and endogenous detection activity (general IHC practice). The supplied HPA and UniProt evidence establishes no SRR-specific retrieval requirement or fixation sensitivity; avoid attributing a weak result to either without comparative evidence. |
| Situation | Likely cause | Next action |
|---|---|---|
| A reported positive cell population is blank. | Purkinje cells, caudate glia and cortical neurons are Medium in HPA tissue IHC; absence of signal could reflect a staining or detection problem (HPA tissue IHC; general IHC practice). | Verify that the intended cells are present, review the antibody’s documented IHC conditions, and check a concurrently stained positive section and detection controls (general IHC practice). Reassess the result against HPA’s pending external verification status. |
| Signal forms a prominent membrane rim. | The pattern conflicts with HPA’s cytoplasmic and nuclear tissue IHC profile and lacks support from SRR topology (HPA tissue IHC; UniProt Q9GZT4 topology). Its cause remains unestablished. | Compare the rim with no-primary and other detection controls, then inspect whether identified positive cells also show the expected intracellular staining (general IHC practice; HPA tissue IHC). Do not score a rim alone as confirmed SRR. |
| A listed Not detected population stains strongly. | Strong staining in oral squamous epithelium, ovarian stroma or smooth muscle cells diverges from HPA’s cell-specific observations (HPA tissue IHC). Cross-reactivity or endogenous chromogenic activity are possibilities (general IHC practice). | Confirm which cells carry the deposit, inspect a no-primary control, and compare with a reported positive population on the same run (general IHC practice; HPA tissue IHC). Treat the discrepancy as unresolved if controls do not explain it. |
| The whole section has a brown haze. | A uniform haze obscures the cell-specific cytoplasmic and nuclear pattern reported by HPA (HPA tissue IHC). Nonspecific binding or detection background can cause diffuse colour (general IHC practice). | Review blocking, antibody concentration, washes and chromogen development; use a no-primary control to locate background introduced during detection (general IHC practice). Score cells only after their staining is separable from the haze. |
| Only one intracellular compartment is convincing. | HPA describes cytoplasmic and nuclear expression across several tissues, but does not require both compartments to be equally intense in every cell (HPA tissue IHC). A compartment difference alone has no established SRR-specific technical cause in the supplied evidence. | Record cytoplasmic and nuclear staining separately in identified cells, compare a reported positive population, and check background controls (HPA tissue IHC; general IHC practice). Avoid converting the ICC-IF vesicle call into an IHC scoring requirement (HPA subcellular). |
| Q: Should vesicular ICC-IF staining define a positive paraffin IHC result? | A: HPA approves vesicular localisation for ICC-IF, while its tissue IHC profile is cytoplasmic and nuclear (HPA subcellular; HPA tissue IHC). The supplied antibodies also carry separate ICC and IHC validation statuses (HPA antibodies). | Assess the chromogenic section using the tissue IHC cell and compartment pattern (HPA tissue IHC). Use the separate IF/ICC guide for fluorescence-specific interpretation; a vesicle-shaped IHC deposit alone does not establish SRR identity. |
Experiment evidence
IHC & IF images showing SRR staining
A02660-2 · IHCIHC analysis of Serine racemase/SRR using anti-Serine racemase/SRR antibody (A02660-2). Serine racemase/SRR was detected in a paraffin-embed
A02660-2 · IFIF analysis of Serine racemase/SRR using anti-Serine racemase/SRR antibody (A02660-2). Serine racemase/SRR was detected in an immunocytochem
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000167720-SRR/tissue/cerebral+cortex#imid_3894240
HPA · CerebellumHuman Protein Atlas IHC, Cerebellum. Source: https://www.proteinatlas.org/ENSG00000167720-SRR/tissue/cerebellum#imid_3894251
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000167720-SRR/tissue/colon#imid_3894174
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000167720-SRR/tissue/liver#imid_3894175
HPA · ICC-IF AF22Human Protein Atlas immunofluorescence, AF22, antibody HPA007529; green = SRR, blue = nucleus, red = microtubules.
HPA · ICC-IF AF22Human Protein Atlas immunofluorescence, AF22, antibody HPA007529; green = SRR, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SRR IHC & IF
🧪Run caudate first and score glial cells for staining (HPA: Medium in caudate glial cells). Use oral mucosa squamous epithelial cells as the negative tissue (HPA: Not detected); on the caudate slide, assess unstained neighboring cells as potential internal negatives without assuming their SRR status.
Positive control tissue: Adipose tissue (Adipocytes, HPA Medium)
Negative control tissue: Oral mucosa (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SRR in AF22, U2OS, with annotated localisation: Vesicles (approved) (HPA subcellular).
Technical controls: Include no-primary (secondary-only) and concentration-matched rabbit IgG isotype controls (caption: rabbit primary antibody), plus SRR-knockout material or a validated peptide-block control as a biological specificity check. Quench endogenous peroxidase and check the caudate slide for pigment that could resemble DAB signal (caption: peroxidase detection with DAB).
⚠️Feasibility: A target-specific fixation window is unreported, and the selected A02660-2 paraffin-section caption does not state the fixative (caption: fixative not stated). Heat retrieval in EDTA at pH 8.0 was used, but retrieval dependence and whether frozen sections or IF/ICC are easier are unreported (caption: heat-mediated EDTA retrieval; HPA: ICC-IF images in AF22 and U2OS). In caudate, inspect pigment separately from chromogenic staining and compare with the no-primary control (HPA: caudate glial cells Medium; caption: DAB chromogen).
HPA tissue IHC evidence for SRR
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Pending external verification.). 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 |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Medium | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
| Caudate | Glial cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Oral mucosa | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
| Ovary | Ovarian stroma cells | Not detected | Protein (IHC) | HPA → |
| Smooth muscle | Smooth muscle 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 SRR IHC Tips
Troubleshoot SRR staining in paraffin sections by checking retrieval, antibody specificity, cell type, and compartment before interpreting chromogenic signal.
What retrieval should I use when SRR staining is weak in paraffin sections?
Start with heat-mediated retrieval in EDTA, pH 8.0, for the catalog antibody (datasheet A02660-2). The selected paraffin-section image used that retrieval, but its caption gives no heating duration, so establish time against a reliably stained control section (datasheet A02660-2; standard IHC practice). Keep section thickness, cooling, and detection conditions constant while comparing retrieval times, because changing several steps obscures the cause of weak staining (standard IHC practice). If signal remains weak, test an alternative retrieval buffer only as a documented fallback and check tissue preservation alongside signal (standard IHC practice). Compare cytoplasmic and nuclear staining patterns with reference tissue rather than accepting stronger diffuse color alone (HPA tissue IHC; standard IHC practice).
Could fixation explain weak or uneven SRR staining?
The selected paraffin-section caption does not report a fixative, so target-specific SRR sensitivity to fixation is unknown (datasheet A02660-2). Record the actual fixative, fixation duration, processing history, and section age before comparing samples; differences can affect antigen access and morphology (standard IHC practice). Run sections with different processing histories through the same EDTA, pH 8.0 retrieval and antibody conditions, using a common control tissue (datasheet A02660-2; standard IHC practice). If staining differs, vary one processing or retrieval condition at a time and assess tissue preservation as well as signal (standard IHC practice). Do not attribute a fixation effect to SRR from its tissue distribution or protein features alone (HPA tissue IHC; UniProt Q9GZT4).
Which compartments and cells should show convincing SRR staining?
Assess SRR signal within identified cells: HPA describes cytoplasmic and nuclear tissue staining, while its cell imaging assigns an approved vesicular location (HPA tissue IHC; HPA subcellular). UniProt gives no subcellular annotation and reports no transmembrane segment, so the record does not establish a membrane-side staining pattern (UniProt Q9GZT4). For an anatomic reference, HPA reports medium staining in cerebellar Purkinje cells and caudate glial cells, with no detection in smooth muscle cells (HPA tissue IHC). Compare those cell populations on matched sections and inspect whether color follows cellular boundaries rather than folds or deposits (standard IHC practice). Treat a new compartment pattern as provisional until controls and independent localization evidence support it (standard IHC practice).
How can epitope choice affect interpretation of SRR staining?
The record lists one 1–340 SRR chain and no annotated isoforms, but the antibody epitope is not supplied here (UniProt Q9GZT4; datasheet A02660-2). SRR has reported modifications at residue 56 and S-nitrosocysteine at residue 113; their effect on this antibody cannot be inferred without epitope information (UniProt Q9GZT4). Ask for the immunogen or mapped epitope before attributing staining differences to modification, and document the answer with the staining conditions (standard IHC practice). Compare a second antibody recognizing a distinct known epitope, if available, on adjacent sections with appropriate negative controls (standard IHC practice). Concordant cell-type and compartment patterns strengthen an assignment, while discordance calls for further specificity checks (standard IHC practice).
How should I adapt SRR localization checks to multiplex IF?
For multiplex IF, pair SRR with a validated marker for the cell population under study, such as a neuronal or glial marker when assessing the reported brain expression (UniProt Q9GZT4; standard IF practice). Choose spectrally separated fluorophores and place a weaker signal in a red or far-red channel after checking unstained-section autofluorescence (standard IF practice). HPA reports vesicular localization in cell imaging, while UniProt reports no transmembrane segment; neither source identifies this antibody’s epitope orientation (HPA subcellular; UniProt Q9GZT4). Titrate permeabilization for access to the epitope’s membrane side, using milder conditions if a cytosol-facing epitope is established and testing stronger access only if needed (standard IF practice). Include single-stain and secondary-only controls before calling puncta or colocalization (standard IF practice).
How do I distinguish SRR staining from chromogenic background?
The selected paraffin-section example used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, and DAB detection (datasheet A02660-2). Its secondary incubation was 30 minutes at 37°C; use those details as a starting reference for this antibody, with matched negative controls (datasheet A02660-2; standard IHC practice). Include a primary-omission control and an endogenous peroxidase block when using HRP and DAB, then inspect pigment and tissue folds separately from cellular staining (standard IHC practice). If background remains high, titrate primary concentration and detection time while keeping retrieval fixed (standard IHC practice). Compare the resulting cell pattern with reported positive and undetected populations before treating widespread brown color as SRR (HPA tissue IHC; standard IHC practice).
How should SRR IHC signal be scored across samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and region before scoring, because SRR staining varies by cell type and tissue in the HPA profile (HPA tissue IHC). For cellular staining, record percent positive cells and an intensity-weighted H-score on a consistent scale; for spatial counts, report positive cells per mm² of viable tissue (standard IHC practice). Score cytoplasmic and nuclear signal separately when both are present, and document whether vesicular puncta can be resolved in the chromogenic preparation (HPA tissue IHC; HPA subcellular; standard IHC practice). Normalize counts to the eligible cells or viable area in each region, excluding folds and necrosis by a preset rule (standard IHC practice). Keep retrieval, detection, counterstain, imaging, and thresholds consistent across the comparison (standard IHC practice).
When is an apparent SRR-positive cell likely to be an artefact?
Call a cell SRR-positive only when staining has a plausible cellular distribution and survives comparison with a primary-omission control (HPA tissue IHC; standard IHC practice). HPA reports cytoplasmic and nuclear tissue expression and vesicular localization in cell imaging, so an isolated surface deposit or edge-only signal needs scrutiny (HPA tissue IHC; HPA subcellular; standard IHC practice). Check cell identity against reported examples, including Purkinje cells and caudate glia, while recognizing that these patterns are reference observations rather than universal rules (HPA tissue IHC). Exclude necrotic regions, folds, and endogenous peroxidase signal before interpreting DAB color as specific staining (standard IHC practice). If the result conflicts with expected cell type or compartment, repeat with matched controls and seek independent specificity evidence (standard IHC practice).
Boster reagents
Best SRR / Serine racemase IHC Antibodies
A02660-2 has SRR staining images from human paraffin-embedded breast cancer tissue and U2OS cells (IHC and IF captions). It lists Human, Mouse, and Rat reactivity (catalog: reactivity).
Real IHC data
Anti-Serine racemase/SRR Antibody ®
Cat # A02660-2
A02660-2 will render with its IHC image from a human breast cancer paraffin section (A02660-2 IHC caption). The same SKU lists IF/ICC applications and has an IF image from U2OS cells (catalog: applications; A02660-2 IF caption).
Which to pick: For tissue IHC, choose A02660-2: its image documents a human breast cancer paraffin section with EDTA retrieval at pH 8.0 and 2 μg/ml primary antibody; the fixative is unreported (A02660-2 IHC caption). For IF/ICC, A02660-2 lists both applications and shows U2OS-cell IF at 5 μg/ml (catalog: applications; A02660-2 IF caption). For cross-species work, A02660-2 lists Human, Mouse, and Rat reactivity, while its IHC-P dilution is specified for Human (catalog: reactivity and dilution).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9GZT4 (SRR_HUMAN, Serine racemase).
- Human Protein Atlas. SRR tissue IHC expression (reliability: Approved).
- Human Protein Atlas. SRR subcellular location (ICC-IF): Localized to vesicles..
- Human Protein Atlas. SRR antibody validation summary (2 antibodies).
- Intra-Brain and Plasma Levels of L-Serine Are Associated with Cognitive Status in Patients with Chronic Kidney Disease. Kidney diseases (Basel, Switzerland) 2023 — PMC10090982.
- Urinary D-asparagine level is decreased by the presence of glioblastoma. Acta neuropathologica communications 2024 — PMC11337596.
- Strontium ranelate promotes chondrogenesis through inhibition of the Wnt/β-catenin pathway. Stem cell research & therapy 2021 — PMC8139050.
- Serine racemase deletion attenuates neurodegeneration and microvascular damage in diabetic retinopathy. PloS one 2018 — PMC5755926.
- PubMed PMID:11054547 — UniProt-cited evidence.
- PubMed PMID:15193426 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SRR (Serine racemase). Expected localisation Cytoplasmic and nuclear tissue staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A02660-2). Validated IHC antibody: A02660-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative Oral mucosa. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human breast cancer tissue; fixative not specified (datasheet A02660-2); 2. Fixation: Image fixative and duration unreported (datasheet A02660-2); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet A02660-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A02660-2); 8. Primary antibody: Rabbit anti-SRR, 2-5 μg/ml (datasheet A02660-2); 9. Primary incubation: Overnight at 4 °C (datasheet A02660-2). Watch for: Fixation: Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific); Caveat: Cell-type variation: oral squamous cells are undetected (HPA tissue IHC); Isoform / epitope: One 1–340 chain; no isoforms or signal peptide annotated (UniProt); Regulation: Higher in schizophrenia DLPFC (UniProt). Evidence: UniProt Q9GZT4, HPA tissue IHC · Approved, HPA ICC-IF · vesicles., Datasheet A02660-2, PMC10090982, PMC11337596. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SRR/immunohistochemistry-ihc-guide.