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RBM42 / RNA-binding protein 42 · IHC design guide
Design Immunohistochemistry for RBM42
Plan chromogenic RBM42 IHC in paraffin sections around the general nuclear tissue pattern (HPA tissue IHC). This guide identifies high staining in adipocytes and glandular cells, a cardiomyocyte comparison with no detected staining, and an IHC-tested catalog antibody (HPA tissue IHC; datasheet A14229-1).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
RBM42 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 | General nuclear tissue staining (HPA tissue IHC) | |
| Staining pattern | Nuclear staining in adipocytes and glandular cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A14229-1) | |
| Positive control | Adipose tissue+4 more · see all | |
| Negative control | Heart muscle |
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 | Stress may shift RBM42 into cytoplasmic granules (UniProt) | |
| Regulation | Intensity regulation unreported (UniProt) | |
| Isoform / epitope | 4 isoforms; epitope coverage is unreported (UniProt) |
Section 1
Recommended RBM42 IHC & IF Protocols
The catalog antibody protocol uses EDTA retrieval (datasheet: A14229-1). A published human PDAC tissue microarray protocol provides a citrate retrieval comparison (PMC12758615).
| Sample | Paraffin-embedded human cervix squamous cell carcinoma tissue; fixative not specified (datasheet A14229-1) |
| Fixation | Image fixative and duration unreported (datasheet A14229-1); 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 A14229-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A14229-1) |
| Primary antibody | Rabbit anti-RBM42, 2-5 μg/ml (datasheet A14229-1) |
| Primary incubation | Overnight at 4 °C (datasheet A14229-1) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A14229-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | RBM42-positive staining in adipocytes of adipose tissue (HPA tissue IHC: High). HPA tissue profile: General nuclear expression. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 HIER for the catalog antibody (datasheet: A14229-1); use sodium citrate retrieval to reproduce the published method (PMC12758615).
Section 2
What Is the Expected RBM42 Staining Pattern?
RBM42 should show predominantly nuclear staining in paraffin sections, including adipocytes, glandular cells, and glial cells reported as high by HPA (HPA tissue IHC: general nuclear expression; High in these cells). Cytoplasmic localization is also reported (UniProt Q9BTD8: nucleus and cytoplasm). The tissue pattern is rated Supported because staining agrees with RNA expression (HPA tissue IHC: Supported). RBM42 has no transmembrane segment (UniProt Q9BTD8 topology).
| Nuclear staining in adipocytes, glandular cells, or glial cells, with identifiable nuclei and limited background. | This matches the expected compartment and reported high-staining cell types (HPA tissue IHC: general nuclear expression; High in these cells). Judge the pattern in the relevant cells rather than treating every cell in a section as equally positive (general IHC interpretation). |
| Staining is confined to cell borders or other structures outside nuclei, while expected nuclear staining is absent. | A border-only pattern conflicts with general nuclear expression and with a protein lacking a transmembrane segment (HPA tissue IHC: general nuclear expression; UniProt Q9BTD8 topology). Treat it as suspect and check detection controls before assigning it to RBM42 (general IHC practice). |
| Strong signal appears in cardiomyocytes despite little or no nuclear staining in a known-positive cell population. | HPA reports RBM42 as not detected in cardiomyocytes (HPA tissue IHC: Heart muscle, cardiomyocytes, Not detected). Consider cross-reactivity or endogenous detection activity and assess controls; this reference observation does not make every cardiomyocyte signal impossible (general IHC interpretation). |
| Color spreads across nuclei, cytoplasm, and extracellular areas without clear cell boundaries. | Diffuse staining is difficult to score as RBM42 because the reported tissue pattern is generally nuclear (HPA tissue IHC: general nuclear expression). Excess detection background or insufficient washing may contribute; compare negative controls and inspect the counterstain (general IHC practice). |
| No convincing signal appears in a section containing a reported high-staining cell type. | Absence of nuclear signal conflicts with the reported pattern for that cell type (HPA tissue IHC: High in adipocytes, glandular cells, and glial cells). Check section quality and assay controls before interpreting it as biological absence (general IHC practice). |
💡Expected RBM42 appearanceCall the result positive when distinct nuclei stain in an HPA high-staining cell type, with any cytoplasmic signal interpreted in context; isolated border or diffuse extracellular color is suspect (HPA tissue IHC: general nuclear expression; High in listed cells; UniProt Q9BTD8: cytoplasm; general IHC interpretation).
| Tissue and cell selection | Adipocytes, glandular cells in the listed organs, and cerebral-cortex glial cells offer reported high-staining populations (HPA tissue IHC: High). Cardiomyocytes are reported as not detected, so interpret heart muscle as a reference pattern rather than a universal negative control (HPA tissue IHC: Heart muscle, Not detected). |
| Compartment and cell state | Predominant nuclear staining fits tissue IHC (HPA tissue IHC: general nuclear expression). RBM42 can also localize to cytoplasm and, upon stress response, to stress granules with HNRNPK (UniProt Q9BTD8: subcellular location). Do not assume that cytoplasmic puncta in an unstressed paraffin section are stress granules. |
| Antibody evidence | The HPA tissue pattern has Supported reliability, and HPA043671 is listed as IHC Supported (HPA tissue IHC: Supported; HPA antibodies: HPA043671, IHC Supported). These ratings support pattern interpretation but do not establish performance for every antibody or staining run. |
| Isoforms and epitope | UniProt lists four RBM42 isoforms and an RRM at residues 381–459 (UniProt Q9BTD8: isoforms; domain). The supplied evidence gives no antibody epitope, so it cannot establish which isoforms a particular antibody detects or predict an isoform-specific IHC pattern. |
| IF/ICC Q&A: what localization is expected? | Mainly nucleoplasmic signal, with additional cytosolic signal, is reported in ICC-IF (HPA subcellular: Nucleoplasm and Cytosol, approved). Those images support a localization comparison; they do not specify a paraffin-section staining procedure or override the tissue IHC pattern. |
| Situation | Likely cause | Next action |
|---|---|---|
| No nuclear staining in a reported high-staining population. | The assay may have failed, or the chosen section may lack enough intact target cells (general IHC interpretation). | Confirm the cell type and section integrity, then review the antibody's documented IHC-P procedure and run controls (general IHC practice; HPA tissue IHC: High in listed cell types). |
| Signal is mainly at cell borders. | That distribution disagrees with general nuclear expression and the absence of a transmembrane segment (HPA tissue IHC: general nuclear expression; UniProt Q9BTD8 topology). | Check a negative detection control and reassess nuclear counterstaining before scoring the border signal as RBM42 (general IHC practice). |
| Cardiomyocytes stain strongly. | HPA reports no detected staining in cardiomyocytes; cross-reactivity or endogenous detection activity are possibilities (HPA tissue IHC: Heart muscle, Not detected; general IHC practice). | Compare reagent omission and detection controls, then assess whether nuclei in a reported high-staining tissue show the expected pattern (general IHC practice; HPA tissue IHC: general nuclear expression). |
| Diffuse color obscures nuclei. | Detection background can prevent compartment scoring (general IHC practice). | Review blocking, washes, detection exposure, and counterstain using the assay's controls; score only cells whose nuclear boundaries remain interpretable (general IHC practice). |
| Cytoplasmic puncta dominate the section. | Stress granules are a possible RBM42 location during stress, but puncta alone do not identify them (UniProt Q9BTD8: stress-response localization). | Check whether nuclear staining and appropriate controls also support RBM42 detection; describe the puncta without assigning a stress-granule identity from IHC alone (HPA tissue IHC: general nuclear expression; general IHC interpretation). |
| An IF image appears more cytosolic than the tissue IHC section. | HPA reports cytosol as an additional ICC-IF location while describing tissue IHC as generally nuclear (HPA subcellular: Cytosol, approved; HPA tissue IHC: general nuclear expression). | Compare each result with its own assay and cell context; use the tissue IHC nuclear pattern when scoring paraffin sections (HPA tissue IHC: general nuclear expression; general IHC interpretation). |
Experiment evidence
IHC & IF images showing RBM42 staining
A14229-1 · IHCIHC analysis of RBM42 using anti-RBM42 antibody (A14229-1). RBM42 was detected in a paraffin-embedded section of human cervix squamous cell
A14229-1 · IHCIHC analysis of RBM42 using anti-RBM42 antibody (A14229-1). RBM42 was detected in a paraffin-embedded section of human prostate adenocarcino
A14229-1 · IFIF analysis of RBM42 using anti-RBM42 antibody (A14229-1) and anti-Beta Tubulin antibody (M01857-3). RBM42 was detected in immunocytochemica
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000126254-RBM42/tissue/cerebral+cortex#imid_11670715
HPA · StomachHuman Protein Atlas IHC, Stomach. Source: https://www.proteinatlas.org/ENSG00000126254-RBM42/tissue/stomach+1#imid_11670623
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000126254-RBM42/tissue/colon#imid_11670641
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000126254-RBM42/tissue/liver#imid_11670658
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA043671; green = RBM42, blue = nucleus, red = microtubules.
HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA043671; green = RBM42, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for RBM42 IHC & IF
🧪Run cervix first: glandular cells should stain (HPA: High in cervix glandular cells), with predominantly nucleoplasmic signal expected (HPA: nucleoplasm approved). Run heart muscle as the negative tissue (HPA: Not detected in cardiomyocytes); cells without specific signal on the cervix slide should show only background staining.
Positive control tissue: Adipose tissue (Adipocytes, HPA High)
Negative control tissue: Heart muscle (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show RBM42 in A-431, U-251MG, U2OS, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only control, a host-matched nonimmune rabbit IgG control (selected-SKU caption: rabbit anti-RBM42), and RBM42 knockout material as a biological negative. Quench endogenous peroxidase before chromogenic detection and check the cervix control slide for residual background (standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected-SKU tissue-IHC caption does not state a fixative. The paraffin-section example used heat retrieval in EDTA at pH 8.0 (selected-SKU tissue-IHC caption); neither frozen sections nor IF can be judged easier from the supplied evidence, although ICC-IF images exist for A-431, U-251MG and U2OS (HPA: subcellular). Score cervix glandular cells separately from squamous carcinoma: the HPA positive row identifies glandular cells, while the selected-SKU image uses cervix squamous cell carcinoma (HPA: High in cervix glandular cells; selected-SKU tissue-IHC caption).
HPA tissue IHC evidence for RBM42
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — High 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 |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | High | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | High | Protein (IHC) | HPA → |
| Breast | Glandular cells | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
| Cervix | Glandular cells | High | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Heart muscle | Cardiomyocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced RBM42 IHC Tips
Use nuclear staining as the main RBM42 readout in chromogenic paraffin IHC, with compartment and tissue controls to evaluate unexpected signal.
What retrieval conditions should I try first if RBM42 staining is weak?
Start with heat-mediated antigen retrieval in EDTA, pH 8.0, for paraffin sections (datasheet A14229-1). The selected tissue image used this retrieval before incubation with 2 μg/ml antibody overnight at 4°C, so reproduce those conditions when troubleshooting weak signal (datasheet A14229-1). Compare retrieved and unretrieved sections from the same specimen to determine whether retrieval improves nuclear contrast without increasing background (standard IHC practice; HPA: general nuclear expression). If staining remains weak, optimize heating and cooling within your validated workflow before testing another buffer or pH as a fallback (standard IHC practice). Keep detection and imaging settings consistent across that comparison so a stronger DAB deposit reflects the retrieval change (standard IHC practice).
Could fixation explain weak or uneven RBM42 staining?
RBM42-specific fixation sensitivity is unknown: the selected paraffin-section caption does not state a fixative, and the other supplied records do not establish fixation conditions (datasheet A14229-1: fixative unreported). Record the specimen’s actual fixative and processing history before changing the staining protocol (standard IHC practice). For comparable paraffin sections, assess whether poorly preserved morphology, section folds, or variable staining across the same tissue accompany the weak nuclear signal (standard IHC practice; HPA: general nuclear expression). Compare specimens with known processing histories under the same EDTA, pH 8.0 retrieval and antibody conditions (datasheet A14229-1; standard IHC practice). Do not assign a target-specific fixation effect from tissue staining patterns alone (HPA: tissue IHC profile).
Where should I expect RBM42 staining, and how should I assess cytoplasmic signal?
Score nucleoplasmic staining first because the tissue profile describes general nuclear expression and the subcellular record approves nucleoplasm as the main location (HPA: tissue IHC; HPA: subcellular). Cytosolic staining is possible, but evaluate it separately from nuclear staining rather than treating both compartments as one positive score (HPA: subcellular; standard IHC practice). Under stress, RBM42 can localize with HNRNPK in cytoplasmic stress granules, so punctate cytoplasmic DAB requires suitable biological context and controls (UniProt Q9BTD8: stress response). Compare compartment patterns in intact cells, away from damaged edges, with a no-primary control (standard IHC practice). RBM42 has no transmembrane segment, so dominant membrane outlining warrants investigation (UniProt Q9BTD8: topology).
Could isoforms or epitope accessibility explain discordant staining?
RBM42 has 4 annotated isoforms and an RRM spanning residues 381–459; without a supplied antibody epitope, isoform coverage cannot be assumed (UniProt Q9BTD8: isoforms and domains; datasheet A14229-1: epitope unreported). Check whether the antibody’s documented immunogen, if available, is shared by the isoforms relevant to the study (standard IHC practice). The record lists phosphorylation and arginine methylation sites, but it supplies no evidence that these modifications alter this antibody’s tissue staining (UniProt Q9BTD8: modified residues). If two antibodies disagree, compare their stated epitopes, retrieval requirements, and nuclear patterns on adjacent sections (standard IHC practice; HPA: general nuclear expression). Report unresolved epitope coverage as a limitation of the interpretation (standard IHC practice).
How can I compare RBM42 immunofluorescence with the chromogenic IHC result?
Use the IHC result as a compartment reference: the expected main location is nucleoplasm, with additional cytosol reported in IF (HPA: tissue IHC; HPA: subcellular). For multiplex IF, pair RBM42 with a validated marker for the cell type under study and keep that marker in a distinct channel (standard IF practice). Choose fluorophores and imaging settings after checking the specimen’s autofluorescence, especially before interpreting faint cytoplasmic signal (standard IF practice; HPA: subcellular). Because RBM42 has no transmembrane segment and is mainly nucleoplasmic, include a permeabilisation step suitable for intracellular nuclear epitopes (UniProt Q9BTD8: topology; HPA: subcellular; standard IF practice). Optimize IF fixation and antibody conditions independently of the paraffin IHC caption (datasheet A14229-1: paraffin IHC conditions).
How do I distinguish diffuse DAB background from RBM42 signal?
Judge signal against the expected predominantly nuclear pattern; uniform haze outside cells or staining that persists without primary antibody suggests background (HPA: general nuclear expression; standard IHC practice). The selected image used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, and an anti-rabbit secondary for 30 minutes at 37°C (datasheet A14229-1). Reproduce those stated conditions before adjusting antibody concentration, blocking, or washing one variable at a time (datasheet A14229-1; standard IHC practice). Include a no-primary control and a peroxidase block when using HRP with DAB to identify detection-related deposit (standard IHC practice; datasheet A14229-1: HRP/DAB). Check whether apparent cytoplasmic haze resolves at higher magnification before scoring it (standard IHC practice; HPA: additional cytosol).
How should I quantify nuclear RBM42 staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cells and compartments before scoring, since RBM42 shows general nuclear expression with additional cytosolic localization reported (HPA: tissue IHC; HPA: subcellular). For nuclear DAB, record the percentage of positive eligible nuclei and staining intensity, then calculate an H-score if its intensity categories are defined in advance (standard IHC practice). Normalize each percentage to the total count of eligible, intact cells in the same annotated region, excluding necrotic and poorly preserved areas (standard IHC practice). If reporting positive-cell density per mm², use the measured viable tissue area as its denominator (standard IHC practice). Keep acquisition, thresholds, counterstain assessment, and region selection consistent across specimens (standard IHC practice).
What would make an apparent RBM42-positive result unconvincing?
A credible result should include staining in the expected nuclear compartment and a pattern compatible with the reported tissue profile (HPA: general nuclear expression; HPA: Supported tissue IHC). The profile reports high staining in several specified cell populations, including cervix glandular cells, while cardiomyocytes in heart muscle are reported as not detected; compare only the relevant cells when those tissues are available (HPA: tissue IHC). Dominant membrane outlining is discordant with the supplied topology, whereas cytosolic signal can occur and merits separate evaluation (UniProt Q9BTD8: no transmembrane segment; HPA: subcellular). Treat edge staining, necrotic deposits, and signal in a no-primary control as possible artefacts (standard IHC practice). With HRP/DAB detection, check peroxidase blocking before attributing residual deposits to RBM42 (standard IHC practice; datasheet A14229-1: HRP/DAB).
Boster reagents
Best RBM42 / RNA-binding protein 42 IHC Antibodies
A14229-1 has IHC images from human and mouse paraffin sections and an IF/ICC image from HeLa cells (catalog image captions); its listed reactivity includes rat (datasheet: reactivity).
Real IHC data
Anti-RBM42 Antibody ®
Cat # A14229-1
A14229-1 will render with an IHC figure from a human cervix squamous cell carcinoma paraffin section (catalog IHC caption). Additional IHC captions show human prostate adenocarcinoma, human spleen and mouse stomach paraffin sections; an IF/ICC caption shows HeLa cells (catalog image captions).
Which to pick: Choose A14229-1 for paraffin section IHC: its human cervix squamous cell carcinoma caption documents EDTA retrieval at pH 8.0 and primary antibody at 2 μg/ml (catalog IHC caption); the fixative is unreported (catalog IHC caption). Choose the same SKU for IF/ICC in HeLa cells, shown at 5 μg/ml (catalog IF/ICC caption). For cross species work, A14229-1 lists human, mouse and rat reactivity, with IHC images from human and mouse sections; rat IHC is listed but has no supplied image, and clonality is unreported (datasheet: reactivity and IHC applications; catalog IHC captions; catalog clone field).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9BTD8 (RBM42_HUMAN, RNA-binding protein 42).
- Human Protein Atlas. RBM42 tissue IHC expression (reliability: Supported).
- Human Protein Atlas. RBM42 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
- Human Protein Atlas. RBM42 antibody validation summary (1 antibodies).
- Functional screen identifies RBM42 as a mediator of oncogenic mRNA translation specificity. Nature cell biology 2025 — PMC12758615.
- PubMed PMID:15057824 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
- PubMed PMID:19413330 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for RBM42 (RNA-binding protein 42). Expected localisation General nuclear tissue staining (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A14229-1). Validated IHC antibody: A14229-1 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adipose tissue (Adipocytes); negative Heart muscle. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human cervix squamous cell carcinoma tissue; fixative not specified (datasheet A14229-1); 2. Fixation: Image fixative and duration unreported (datasheet A14229-1); 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 A14229-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A14229-1); 8. Primary antibody: Rabbit anti-RBM42, 2-5 μg/ml (datasheet A14229-1); 9. Primary incubation: Overnight at 4 °C (datasheet A14229-1). Watch for: Fixation: Keep fixation consistent across paraffin sections (standard IHC practice; not target-specific); Caveat: Stress may shift RBM42 into cytoplasmic granules (UniProt); Isoform / epitope: 4 isoforms; epitope coverage is unreported (UniProt); Regulation: Intensity regulation unreported (UniProt). Evidence: UniProt Q9BTD8, HPA tissue IHC · Supported, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A14229-1, PMC12758615. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/RBM42/immunohistochemistry-ihc-guide.