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SRI / Sorcin · IHC design guide
Design Immunohistochemistry for SRI
Plan chromogenic SRI IHC on paraffin sections with the catalog antibody at 0.5–1 μg/mL (datasheet A00222). Use the reported cytoplasmic and nuclear tissue pattern to assess staining, while accounting for calcium-dependent recruitment to the sarcoplasmic reticulum membrane (HPA tissue IHC; UniProt).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
SRI 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 | Cytoplasm and nuclei in brain, bladder, fallopian tube and gut (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6 HIER, heat-mediated (datasheet A00222) | |
| Positive control | Appendix+4 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A00222) | |
| Caveat | Cardiac myocytes: reported by UniProt, undetected by HPA IHC (UniProt; HPA tissue IHC) | |
| Regulation | Elevated Ca²⁺ recruits SRI to the SR membrane (UniProt) | |
| Isoform / epitope | 3 isoforms; antibody epitope coverage is unspecified (UniProt) |
Section 1
Recommended SRI IHC & IF Protocols
The catalog antibody’s IHC-P protocol uses citrate retrieval (datasheet A00222). Three published Sorcin IHC protocols provide additional conditions for gallbladder, prostate, and paraffin tissue sections (PMC13115428; PMC12257818; PMC11241191).
| Sample | Paraffin-embedded human intestinal cancer tissues; fixative not specified (datasheet A00222) |
| Fixation | Image fixative and duration unreported (datasheet A00222); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: Citrate pH 6, 20 min (datasheet A00222) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A00222) |
| Primary antibody | Rabbit anti-SRI, 0.5-1μg/ml (datasheet A00222) |
| Primary incubation | Overnight at 4 °C (datasheet A00222) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A00222) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | SRI-positive staining in enterocytes - Microvilli of appendix (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic and nuclear expression expression in the brain, urinary bladder, fallopian tube and the gastrointestinal tract. No signal in the no-primary control. |
💡Decision noteStart with pH 6 citrate heat retrieval for the catalog antibody (datasheet A00222). The gallbladder protocol used pH 9.0 Tris with a different primary (PMC13115428).
Section 2
What Is the Expected SRI Staining Pattern?
In paraffin-section IHC, expect SRI staining mainly in the cytoplasm of selected cells, with nuclear staining also reported across several tissues (HPA: tissue IHC profile). High-staining examples include glial cells, fallopian-tube ciliated cell bodies and rectal endocrine cells (HPA: High). Sorcin is cytoplasmic and can relocate to the sarcoplasmic reticulum membrane as calcium rises; it has no transmembrane segment (UniProt P30626: localization and topology). HPA rates tissue-IHC reliability as Enhanced (HPA: reliability).
| Clear cytoplasmic staining in glial cells or fallopian-tube ciliated cell bodies. | This matches cells scored High by HPA. Compare signal with adjacent cell types on the same section; a positive result need not stain every cell (HPA: tissue IHC). |
| Cytoplasmic staining with some nuclear staining in the expected tissue and cell types. | HPA reports both compartments in its tissue profile. Interpret nuclear signal alongside cell identity and controls; nucleoplasmic ICC-IF localization is uncertain (HPA: tissue IHC; HPA: subcellular). |
| Predominantly extracellular or luminal deposit with little staining inside expected positive cells. | That distribution does not fit the reported cellular locations. Check for nonspecific precipitate or detection background before calling it SRI (UniProt P30626: localization; HPA: tissue IHC; standard IHC practice). |
| Strong staining in a cell type HPA scores Not detected, such as adipocytes. | Treat the result as unexpected for that cell type; cross-reactivity or endogenous detection activity is possible. Review controls before assigning target expression (HPA: adipocytes Not detected; standard IHC practice). |
| No staining in an HPA High cell population, despite an interpretable section. | A missing positive calls the run into question. Check tissue identity, antibody and detection controls before concluding SRI is absent (HPA: High cell populations; standard IHC practice). |
💡Expected SRI appearanceCall a convincing positive when discrete intracellular staining is evident in an HPA High population, such as glial cells or fallopian-tube ciliated cell bodies; cytoplasmic signal is expected and nuclear signal can occur, whereas extracellular deposit or uniform staining across unrelated cells is suspect (HPA: tissue IHC profile and High scores; UniProt P30626: localization; standard IHC practice).
| Cell type and tissue selection (HPA: tissue IHC). | HPA scores glial cells and fallopian-tube ciliated cell bodies High, but adipocytes Not detected. Select controls by the scored cell type, not tissue name alone (HPA: tissue IHC). |
| Subcellular distribution (UniProt P30626; HPA: subcellular). | Cytoplasmic signal agrees with both sources. Calcium-dependent sarcoplasmic-reticulum association is reported by UniProt; HPA's nucleoplasmic ICC-IF call is uncertain (UniProt P30626: localization; HPA: subcellular). |
| Antibody validation (HPA: antibodies). | HPA019004 and HPA073666 each have Enhanced IHC status. That supports the reported tissue pattern but does not establish specificity for a different catalog antibody (HPA: antibodies and tissue reliability). |
| Isoforms and epitope coverage (UniProt P30626). | UniProt lists three isoforms. Epitope position and isoform coverage are not supplied here, so do not infer which isoforms an IHC result detects (UniProt P30626: isoforms). |
| Heart interpretation (UniProt P30626; HPA: heart muscle). | UniProt reports detection in cardiac myocytes, while HPA scores heart-muscle cardiomyocytes Not detected by tissue IHC. Keep both observations visible; neither alone resolves a new slide (UniProt P30626: tissue specificity; HPA: heart muscle). |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in a section expected to contain HPA High glial cells. | The chosen field may lack the scored cells, or the IHC run may have failed; the slide alone cannot distinguish these causes (HPA: glial cells High; standard IHC practice). | Confirm cell identity, then review the run's positive and detection controls. If controls fail, repeat using the antibody's validated IHC-P conditions (HPA: glial cells High; standard IHC practice). |
| Weak or patchy staining in a purported positive tissue. | HPA scores specific cell populations, so tissue-wide staining is not required. Processing or detection variation is another general possibility (HPA: tissue IHC; standard IHC practice). | Score the named cells in intact areas and compare them with the same-run positive control. Review general IHC steps if that control is weak (HPA: tissue IHC; standard IHC practice). |
| Brown signal covers many unrelated cells or obscures morphology. | Diffuse background can arise from nonspecific antibody binding or endogenous chromogenic detection activity (standard IHC practice). | Inspect a no-primary control and the detection-only control; adjust general blocking, washing or detection conditions if background persists (standard IHC practice). |
| An HPA Not detected cell type stains strongly. | Cross-reactivity or endogenous activity is possible; an HPA Not detected score is an observation, not proof that all samples must be blank (HPA: tissue IHC; standard IHC practice). | Compare the scored cell type and controls, then seek an independent antibody or orthogonal evidence before assigning SRI expression (HPA: tissue IHC and antibody validation; standard IHC practice). |
| Cardiomyocytes stain, despite HPA's Not detected IHC score. | The sources differ: UniProt reports detection in cardiac myocytes, whereas HPA records no cardiomyocyte IHC staining in heart muscle (UniProt P30626: tissue specificity; HPA: heart muscle). | Record the discrepancy and check controls and cell identity. Do not label the signal either confirmed or artifactual from those two source statements alone (UniProt P30626; HPA: heart muscle; standard IHC practice). |
| Q: Does nucleoplasmic signal in IF/ICC confirm the paraffin-section IHC pattern? | A: HPA lists nucleoplasm as uncertain in ICC-IF, although its tissue-IHC profile includes nuclear expression (HPA: subcellular; HPA: tissue IHC). | Interpret IF/ICC on its own guide page with its own controls; do not transfer its compartment confidence directly to IHC scoring (HPA: subcellular and tissue IHC; standard IHC practice). |
Experiment evidence
IHC & IF images showing SRI staining
A00222 · IHCIHC analysis of SRI using anti-SRI antibody (A00222). SRI was detected in paraffin-embedded section of human intestinal cancer tissues. Heat
A00222 · IHCIHC analysis of SRI using anti-SRI antibody (A00222). SRI was detected in paraffin-embedded section of human lung cancer tissues. Heat media
A00222 · IFIF analysis of SRI using anti-SRI antibody (A00222) SRI was detected in immunocytochemical section of U20S cell. Enzyme antigen retrieval wa
A00222-2 · IFIF analysis of SRI using anti-SRI antibody (A00222-2). SRI was detected in an immunocytochemical section of SiHa cells. Enzyme antigen retri
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000075142-SRI/tissue/cerebral+cortex#imid_19908280
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000075142-SRI/tissue/colon#imid_19892639
HPA · RectumHuman Protein Atlas IHC, Rectum. Source: https://www.proteinatlas.org/ENSG00000075142-SRI/tissue/rectum#imid_19892623
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000075142-SRI/tissue/liver#imid_19892632
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA019004; green = SRI, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA019004; green = SRI, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for SRI IHC & IF
🧪Run appendix first; enterocyte microvilli should stain strongly (HPA: High in appendix enterocyte microvilli). Use esophagus squamous epithelium as the negative tissue (HPA: Not detected); on the appendix slide, call cells internal negatives only if independently confirmed SRI-negative, and expect background-level DAB staining in those cells (standard IHC practice).
Positive control tissue: Appendix (Enterocytes - Microvilli, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show SRI in A-431, U-251MG, U2OS, NIH 3T3, with annotated localisation: Nucleoplasm (uncertain), Cytosol (supported) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control; a rabbit IgG isotype control matched to the primary antibody’s clonality; and SRI-knockout tissue or validated peptide competition as a biological specificity control (caption: rabbit anti-SRI primary; standard IHC practice). Block endogenous peroxidase and biotin when using the caption’s biotinylated secondary and SABC-DAB detection, since either can produce misleading signal (caption: SABC-DAB detection; standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence, and the selected tissue-IHC caption does not state a fixative (caption: fixative unreported). The caption uses heat retrieval in citrate buffer at pH 6 for 20 minutes, which provides a starting condition but does not establish that retrieval is required (caption: citrate retrieval). The evidence does not establish that frozen sections or IF/ICC are easier; for appendix, check endogenous biotin and peroxidase background when interpreting SABC-DAB staining (caption: SABC-DAB detection; standard IHC practice).
HPA tissue IHC evidence for SRI
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data. Paired antibodies with high similarity supports the protein expression.). 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 | Enterocytes - Microvilli | High | Protein (IHC) | HPA → |
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
| Fallopian tube | Ciliated cells (cell body) | High | Protein (IHC) | HPA → |
| Hippocampus | Glial cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Esophagus | Squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
| Gallbladder | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Heart muscle | Cardiomyocytes | Not detected | Protein (IHC) | HPA → |
| Kidney | Cells in glomeruli | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SRI IHC Tips
Troubleshoot Sorcin staining in paraffin sections by checking retrieval, cell identity, compartment pattern, and matched controls before interpreting chromogenic signal.
What retrieval should I use when Sorcin staining is weak in paraffin sections?
Start with heat mediated retrieval in citrate buffer at pH 6 for 20 minutes (datasheet A00222). The selected paraffin section image used this treatment before overnight incubation with 1 μg/mL antibody at 4°C (datasheet A00222). If staining remains weak, check that sections stayed covered during heating and compare a controlled adjustment of heating time with the original condition (standard IHC practice). Run the same reference tissue and detection steps alongside each retrieval condition so a change in signal can be attributed to retrieval (standard IHC practice). Record tissue preservation as well as staining intensity, because excessive heat can damage section morphology (standard IHC practice).
Could fixation explain weak or patchy Sorcin staining?
Target specific fixation sensitivity is unknown: the selected A00222 paraffin tissue caption does not state a fixative (datasheet A00222). Record the actual fixative, fixation duration, processing history, and section age for each specimen before comparing staining (standard IHC practice). Use sections processed together when testing a change, and keep citrate retrieval at pH 6 for 20 minutes as the starting condition (datasheet A00222; standard IHC practice). If a run gives patchy signal, compare tissue preservation, section adhesion, and reagent coverage across the slide before changing antibody concentration (standard IHC practice). Neither tissue expression data nor protein topology establishes a fixation effect for this antibody (HPA tissue IHC; UniProt P30626 topology).
Which staining compartments should I expect for Sorcin?
Assess cytoplasmic staining first: Sorcin is annotated in the cytoplasm and can relocate to the sarcoplasmic reticulum membrane when calcium rises (UniProt P30626 subcellular). It has no transmembrane segment, so a continuous cell surface rim is not an expected pattern from its annotated topology (UniProt P30626 topology). HPA reports cytoplasmic and nuclear tissue staining, while its cell imaging supports cytosol and labels nucleoplasm uncertain (HPA tissue IHC; HPA subcellular). Compare compartment patterns within intact cells and against a reference section processed in the same run (standard IHC practice). Treat exclusively nuclear or sharply membranous DAB staining as requiring independent validation before assigning it to Sorcin (UniProt P30626 subcellular; HPA subcellular; standard IHC practice).
Can isoforms or epitope accessibility change my IHC result?
Sorcin has 3 annotated isoforms and 4 EF-hand regions spanning residues 29–169 (UniProt P30626 isoforms; UniProt P30626 domains). The supplied evidence does not locate the A00222 epitope or establish which isoforms it detects (datasheet A00222; UniProt P30626 isoforms). Check the antibody's documented immunogen or epitope before interpreting a negative section as absence of every isoform (standard IHC practice). Compare matched sections under the documented citrate pH 6, 20-minute retrieval condition before changing retrieval to investigate accessibility (datasheet A00222; standard IHC practice). Because no glycosylation sites or modified residues are annotated, avoid attributing staining differences to either modification without separate evidence (UniProt P30626 processing).
How should I check Sorcin localisation by multiplex IF?
Use a cell type marker in a separate channel to identify the cells being assessed; HPA reports high Sorcin staining in rectal endocrine cells and fallopian tube ciliated cell bodies (HPA tissue IHC; standard IF practice). Choose fluorophores after inspecting an unstained section for tissue autofluorescence, and include single stain controls to check channel bleed through (standard IF practice). Sorcin is annotated in cytoplasm and at the sarcoplasmic reticulum membrane, with no transmembrane segment (UniProt P30626 subcellular; UniProt P30626 topology). Permeabilise sufficiently to access the intracellular epitope, while treating the antibody's precise epitope location as unknown (UniProt P30626 topology; datasheet A00222; standard IF practice). Compare IF compartments with the documented IHC pattern cautiously because the selected antibody evidence describes paraffin section chromogenic detection (datasheet A00222; standard IF practice).
How can I reduce diffuse DAB or nonspecific Sorcin staining?
Begin by checking the documented conditions: 10% goat serum block, 1 μg/mL primary antibody overnight at 4°C, and biotinylated secondary detection with DAB (datasheet A00222). Include a no primary control and a matched negative tissue to locate signal arising from detection chemistry or tissue background (standard IHC practice; HPA tissue IHC). Block endogenous peroxidase, wash thoroughly, and assess whether DAB development time produces diffuse colour even in controls (standard IHC practice). The documented workflow uses a biotin based detection complex, so evaluate endogenous biotin if background follows particular tissue structures (datasheet A00222; standard IHC practice). If controls are clean but specific cells look hazy, titrate primary antibody around the documented concentration while holding retrieval and imaging settings constant (datasheet A00222; standard IHC practice).
What should I score when comparing Sorcin IHC across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and compartment before scoring, because HPA reports both cytoplasmic and nuclear tissue staining (HPA tissue IHC; standard IHC practice). For cell based comparisons, report the percentage of positive cells and an H-score based on staining intensity within the defined population (standard IHC practice). For spatial questions, report positive cell density per mm² of viable tissue or the specified compartment (standard IHC practice). Normalise to the number of eligible cells or measured viable area, and exclude folds, section edges, and necrosis consistently (standard IHC practice). Keep retrieval, DAB development, counterstain, image capture, and scoring thresholds consistent across groups, using the same reference section to monitor run variation (standard IHC practice).
How do I distinguish genuine Sorcin signal from IHC artefact?
Look for staining in intact cells with a plausible cytoplasmic pattern; Sorcin is annotated in cytoplasm and may associate with sarcoplasmic reticulum membrane under elevated calcium (UniProt P30626 subcellular). Check cell identity because HPA reports high staining in rectal endocrine cells and fallopian tube ciliated cell bodies, while some other listed populations are not detected (HPA tissue IHC). Compare suspicious staining at section edges or in necrotic regions with the interior viable tissue before calling it positive (standard IHC practice). A no primary control helps identify endogenous enzyme activity or detection background that can mimic DAB signal (standard IHC practice). Interpret nuclear staining cautiously because HPA reports it in tissue but rates nucleoplasmic localisation uncertain in cell imaging (HPA tissue IHC; HPA subcellular).
Boster reagents
Best SRI / Sorcin IHC Antibodies
Anti-SRI antibodies have IHC images from human paraffin tissue and IF images from U20S and SiHa cells (catalog image captions); both list human, mouse and rat reactivity (catalog applications/reactivity).
Real IHC data
Anti-SRI Antibody ®
Cat # A00222
Real IF data
Anti-SRI Antibody ®
Cat # A00222-2
A00222 lists IHC and IF applications, with IHC images from human intestinal, lung and mammary cancer paraffin sections and an IF image from U20S cells (catalog applications; A00222 image captions). A00222-2 lists IF/ICC applications and has an IF image from SiHa cells (catalog applications; A00222-2 image caption).
Which to pick: For paraffin tissue IHC, choose A00222: its own caption documents citrate retrieval at pH 6 for 20 minutes and DAB detection; the fixative is unreported (A00222 IHC caption). For IF/ICC, either SKU lists those applications, while A00222-2 has a SiHa cell IF image and no listed IHC application (catalog applications; A00222-2 IF caption). Both list human, mouse and rat reactivity, but the supplied images document human samples only; neither SKU’s clonality is reported (catalog reactivity; catalog image captions; catalog clone fields).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P30626 (SORCN_HUMAN, Sorcin).
- Human Protein Atlas. SRI tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. SRI subcellular location (ICC-IF): Localized to the nucleoplasm and cytosol..
- Human Protein Atlas. SRI antibody validation summary (2 antibodies).
- Protein Expression Analysis and Functional Characterization of Sorcin in Gallbladder Cancer. Cells 2026 — PMC13115428.
- Human epidermal growth factor receptor-2 gene expression positivity determined by silver in situ hybridization/immunohistochemistry methods and associated factors in a cohort of Sri Lankan patients with gastric adenocarcinoma: a prospective study. The Journal of international medical research 2023 — PMC9950620.
- Biochemical and Histological Characterization of Sorcin Overexpression in Patients Who Underwent Radical Prostatectomy. Urology research & practice 2025 — PMC12257818.
- Sorcin Inhibits Mitochondrial Apoptosis by Interacting with STAT3 via NF-κB Pathway. International journal of molecular sciences 2024 — PMC11241191.
- PubMed PMID:7873602 — UniProt-cited evidence.
- PubMed PMID:8561500 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for SRI (Sorcin). Expected localisation Cytoplasmic and nuclear tissue staining (HPA tissue IHC). Antigen retrieval: Citrate pH 6 HIER, heat-mediated (datasheet A00222). Validated IHC antibody: A00222 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Enterocytes - Microvilli); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human intestinal cancer tissues; fixative not specified (datasheet A00222); 2. Fixation: Image fixative and duration unreported (datasheet A00222); 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: Citrate pH 6 , 20 min (datasheet A00222); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A00222); 8. Primary antibody: Rabbit anti-SRI, 0.5-1μg/ml (datasheet A00222); 9. Primary incubation: Overnight at 4 °C (datasheet A00222). Watch for: Fixation: Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A00222); Caveat: Cardiac myocytes: reported by UniProt, undetected by HPA IHC (UniProt; HPA tissue IHC); Isoform / epitope: 3 isoforms; antibody epitope coverage is unspecified (UniProt); Regulation: Elevated Ca²⁺ recruits SRI to the SR membrane (UniProt). Evidence: UniProt P30626, HPA tissue IHC · Enhanced, HPA ICC-IF · nucleoplasm and cytosol., Datasheet A00222, PMC13115428, PMC12257818. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/SRI/immunohistochemistry-ihc-guide.