SRSF11 Antibody

What is SRSF11 and why is it important for research?

SRSF11 (serine/arginine-rich splicing factor 11) is a nuclear protein that functions in pre-mRNA splicing as part of the Splicing factor SR protein family. The canonical human SRSF11 protein has 484 amino acid residues with a calculated molecular weight of 53.5 kDa, though it typically appears at approximately 72 kDa in Western blots due to post-translational modifications. SRSF11 is widely expressed across many tissue types and has up to two reported isoforms . The protein is known by several synonyms including SFRS11, dJ677H15.2, p54, SR splicing factor 11, and NET2 . SRSF11 is important for researchers studying RNA processing, alternative splicing mechanisms, and broader gene expression regulation. Orthologs have been identified in multiple species including mouse, rat, bovine, frog, zebrafish, chimpanzee, and chicken, making it valuable for comparative studies .

What criteria should I consider when selecting an SRSF11 antibody for my research?

When selecting an SRSF11 antibody, consider the following criteria:

• Application compatibility: Verify the antibody is validated for your intended application (WB, IHC, ELISA, ICC, etc.)

• Species reactivity: Ensure compatibility with your experimental model (human, mouse, rat, etc.)

• Target region: Different antibodies target different regions of SRSF11 (e.g., middle region, C-terminal)

• Clonality: Polyclonal antibodies may provide broader epitope recognition, while monoclonals offer higher specificity

• Validation data: Review provided validation images showing specificity and performance in relevant applications

• Immunogen information: Check if the immunogen sequence is disclosed and relevant to your research question

Antibodies targeting different epitopes may yield different results depending on protein conformation, post-translational modifications, or interaction with other proteins in your experimental system.

What are the common applications for SRSF11 antibodies?

SRSF11 antibodies are validated for several experimental applications:

Western blotting is the most widely used application for SRSF11 antibodies, followed by ELISA . The antibody dilutions should be optimized for each specific experiment and antibody lot for optimal signal-to-noise ratio.

How should I optimize Western blot protocols for SRSF11 detection?

For optimal SRSF11 detection by Western blot:

• Sample preparation:

  • Use RIPA or NP-40 buffer with protease inhibitors for whole cell lysates

  • For nuclear proteins like SRSF11, consider nuclear extraction protocols

  • Load 20-50 μg total protein per lane

• Gel selection and transfer:

  • Use 10% SDS-PAGE gels for optimal separation around 72 kDa

  • Transfer to PVDF membrane (preferred over nitrocellulose for nuclear proteins)

  • Transfer at 100V for 1 hour or 30V overnight at 4°C

• Blocking and antibody incubation:

  • Block with 5% non-fat milk or BSA in TBST for 1 hour at room temperature

  • Dilute primary antibody 1:500-1:2000 in blocking buffer

  • Incubate overnight at 4°C with gentle rocking

  • Wash 3-5 times with TBST, 5 minutes each

  • Incubate with HRP-conjugated secondary antibody (1:5000-1:10000) for 1 hour at room temperature

• Visualization and troubleshooting:

  • Expected band size is approximately 72 kDa, despite calculated MW of 53.5 kDa

  • Use positive control tissues/cells with known SRSF11 expression

  • Consider blocking peptide controls to confirm specificity

For challenging samples, inclusion of phosphatase inhibitors may be important as SRSF11 contains potentially phosphorylated serine/arginine residues.

What antigen retrieval methods are recommended for SRSF11 immunohistochemistry?

For optimal SRSF11 detection in fixed tissues:

• Heat-induced epitope retrieval (HIER):

  • Tris-EDTA buffer (pH 9.0) is recommended for SRSF11 antibodies

  • Heat at 95-100°C for 15-20 minutes in pressure cooker or microwave

  • Allow slides to cool in retrieval solution for 20 minutes at room temperature

• Protocol optimization:

  • Paraffin sections should be cut at 4-6 μm thickness

  • Dilute antibody 1:50-1:300 in antibody diluent

  • Incubate overnight at 4°C in humidified chamber

  • Use appropriate detection system (e.g., HRP-polymer with DAB)

• Controls:

  • Include positive control tissue (e.g., squamous cell carcinoma of lung)

  • Include negative control by omitting primary antibody

  • Consider using cell lines with known SRSF11 expression levels

Results should show clear nuclear localization of SRSF11, consistent with its function in pre-mRNA splicing.

How can I validate SRSF11 antibody specificity in my experimental system?

To ensure antibody specificity for SRSF11:

• Positive and negative controls:

  • Use cell lines with known SRSF11 expression (e.g., LOVO, RAW264.7)

  • Include tissue/cells from knockout models if available

  • Compare with another validated antibody targeting a different SRSF11 epitope

• Peptide competition assay:

  • Pre-incubate antibody with excess immunizing peptide

  • Run parallel Western blots or IHC with blocked and unblocked antibody

  • Specific signal should be eliminated or significantly reduced

• siRNA/shRNA knockdown validation:

  • Transfect cells with SRSF11-targeting siRNA/shRNA

  • Confirm knockdown by qRT-PCR

  • Demonstrate corresponding reduction in antibody signal

• Mass spectrometry verification:

  • Perform immunoprecipitation with SRSF11 antibody

  • Analyze precipitated proteins by mass spectrometry

  • Confirm presence of SRSF11 peptides in the immunoprecipitate

Documentation of these validation steps increases confidence in experimental results and may be required for high-impact publications.

How can SRSF11 antibodies be used to study alternative splicing mechanisms?

SRSF11 antibodies can be employed to investigate alternative splicing through several approaches:

• RNA immunoprecipitation (RIP):

  • Cross-link protein-RNA complexes in intact cells

  • Lyse cells and immunoprecipitate with SRSF11 antibody

  • Extract bound RNA and analyze by RT-PCR or sequencing

  • Identify RNA targets directly bound by SRSF11

• Chromatin immunoprecipitation (ChIP):

  • Cross-link protein-DNA complexes

  • Immunoprecipitate with SRSF11 antibody

  • Analyze co-precipitated DNA for association with specific genes

  • Provides insight into co-transcriptional splicing roles

• Immunofluorescence co-localization:

  • Co-stain cells for SRSF11 and other splicing factors

  • Use confocal microscopy to assess co-localization

  • Analyze changes in localization under different conditions

  • Quantify co-localization coefficients (Pearson's or Mander's)

• Proximity ligation assay (PLA):

  • Use SRSF11 antibody with antibodies against other splicing factors

  • Detect protein-protein interactions within 40nm distance

  • Visualize and quantify interaction events in situ

These techniques help elucidate SRSF11's role in exon inclusion/exclusion decisions and its place in the broader splicing regulatory network.

What are the considerations for studying SRSF11 post-translational modifications?

SRSF11 function is likely regulated by post-translational modifications (PTMs), particularly phosphorylation of its serine/arginine-rich domains. When studying these modifications:

• Phosphorylation-specific detection:

  • Use phosphatase inhibitors in all extraction buffers

  • Consider using Phos-tag™ gels for mobility shift detection

  • Look for characteristic doublet or triplet banding patterns

  • Compare migration patterns before/after phosphatase treatment

• Other potential PTMs:

  • Methylation, acetylation, and SUMOylation may affect SR proteins

  • Use appropriate inhibitors to preserve specific modifications

  • Consider enrichment strategies for modified proteins

• Mass spectrometry approaches:

  • Immunoprecipitate SRSF11 from cells under various conditions

  • Perform LC-MS/MS analysis to map modification sites

  • Compare modification patterns after cellular stresses or stimuli

• Functional consequences:

  • Correlate modification states with subcellular localization

  • Examine effects on RNA binding capacity

  • Assess impact on protein-protein interactions

Understanding SRSF11 PTMs helps decipher how splicing regulation is dynamically controlled in response to cellular conditions.

How do I resolve discrepancies between calculated and observed molecular weights for SRSF11?

Researchers often observe SRSF11 at approximately 72 kDa on Western blots despite its calculated molecular weight of 53.5 kDa . This discrepancy is common for SR proteins and can be investigated through:

• Causes of aberrant migration:

  • Post-translational modifications, especially phosphorylation

  • Highly charged regions affecting SDS binding

  • Protein structure affecting electrophoretic mobility

  • Alternative splicing yielding different isoforms

• Investigation approaches:

  • Compare migration patterns in different percentage gels

  • Treat samples with phosphatases before SDS-PAGE

  • Use mass spectrometry to confirm protein identity

  • Compare migration of recombinant versus endogenous protein

• Validation strategies:

  • Use multiple antibodies targeting different epitopes

  • Include appropriate positive controls

  • Perform knockdown/knockout controls

  • Consider using tagged SRSF11 expression constructs

This phenomenon is not unusual for nuclear proteins and particularly common among splicing factors. Careful controls help ensure proper protein identification despite anomalous migration.

How can I improve signal-to-noise ratio in SRSF11 Western blots?

Poor signal-to-noise ratio is a common challenge when detecting SRSF11. To improve results:

• Sample preparation optimization:

  • Use fresh samples whenever possible

  • Include appropriate protease inhibitors

  • Consider nuclear extraction to enrich for SRSF11

  • Avoid repeated freeze-thaw cycles

• Blocking and washing optimization:

  • Try 5% BSA instead of milk for phosphorylated proteins

  • Increase washing duration or number of washes

  • Add 0.05-0.1% SDS to wash buffer for stubborn background

  • Consider using specialized blocking reagents

• Antibody concentration optimization:

  • Perform titration experiments (1:500, 1:1000, 1:2000, etc.)

  • Reduce primary antibody concentration if background is high

  • Reduce secondary antibody concentration to 1:10000 or greater

  • Incubate antibodies at 4°C to improve specificity

• Detection system considerations:

  • Use high-sensitivity ECL reagents for weak signals

  • Consider fluorescent secondary antibodies for better quantification

  • Optimize exposure times when using film detection

Systematic troubleshooting by changing one variable at a time will help identify the source of background or weak signal issues.

What controls should I include when studying SRSF11 in different experimental contexts?

Proper controls are essential for reliable SRSF11 research:

• Positive controls:

  • Cell lines with confirmed SRSF11 expression (LOVO, RAW264.7)

  • Tissues with known SRSF11 expression patterns

  • Recombinant SRSF11 protein (when available)

• Negative controls:

  • SRSF11 knockdown/knockout samples

  • Secondary antibody-only controls

  • Isotype controls for immunoprecipitation

  • Peptide competition controls

• Normalization controls:

  • Housekeeping proteins for Western blot (β-actin, GAPDH)

  • Specific subcellular markers (lamin for nuclear fraction)

  • Loading controls appropriate to fractionation method

• Cross-validation approaches:

  • Multiple antibodies targeting different SRSF11 epitopes

  • Orthogonal detection methods (mass spectrometry)

  • Correlation with mRNA expression levels

Proper controls not only validate findings but also help troubleshoot when experiments yield unexpected results.

What are the potential cross-reactivity concerns with SRSF11 antibodies?

SR proteins share structural similarities that may lead to antibody cross-reactivity. Address these concerns through:

• Cross-reactivity assessment:

  • Check immunogen sequence against other SR family members

  • Test antibody against recombinant SR proteins if available

  • Include SRSF11 knockout/knockdown controls

  • Consider testing in species with divergent SRSF11 sequences

• Epitope considerations:

  • Antibodies raised against highly conserved domains may cross-react

  • C-terminal targeted antibodies may offer better specificity

  • Compare results from antibodies targeting different epitopes

• Validation in your experimental system:

  • Perform immunoprecipitation followed by mass spectrometry

  • Use siRNA against SRSF11 and related SR proteins

  • Compare banding patterns with predicted molecular weights

• Application-specific optimization:

  • More stringent washing for immunohistochemistry

  • Higher antibody dilutions to reduce non-specific binding

  • Different blocking agents to minimize background

Understanding the specific epitope recognized by your antibody helps predict and manage potential cross-reactivity issues.

How can SRSF11 antibodies be used to investigate splicing dysregulation in cancer?

SRSF11 antibodies can provide valuable insights into cancer-associated splicing dysregulation:

• Expression analysis in cancer tissues:

  • Compare SRSF11 levels between tumor and adjacent normal tissue

  • Correlate expression with clinical parameters and outcomes

  • Assess nuclear/cytoplasmic distribution in tumor samples

• Functional studies in cancer cell lines:

  • Manipulate SRSF11 levels and assess effects on cancer-associated splicing events

  • Use immunoprecipitation to identify cancer-specific SRSF11 interactors

  • Monitor SRSF11 localization in response to chemotherapeutic agents

• Potential as biomarker:

  • Standardize IHC protocols for diagnostic applications

  • Develop scoring systems based on expression levels and localization

  • Correlate with other splicing factor alterations

• Therapeutic targeting assessment:

  • Monitor SRSF11 levels/modifications after treatment with splicing modulators

  • Study resistance mechanisms involving SRSF11-mediated splicing changes

  • Identify synthetic lethal interactions with SRSF11 modulation

Evidence from squamous cell carcinoma of lung tissue staining suggests SRSF11 may have altered expression or localization in certain cancer types .

What methodological approaches can reveal SRSF11 interactions with other splicing factors?

Understanding SRSF11's place in the splicing machinery requires investigating its protein interactions:

• Co-immunoprecipitation (Co-IP):

  • Use SRSF11 antibody to pull down protein complexes

  • Analyze by Western blot for known splicing factors

  • Perform mass spectrometry for unbiased interaction mapping

  • Compare interaction profiles under different cellular conditions

• Proximity-dependent labeling:

  • Generate BioID or APEX2 fusions with SRSF11

  • Identify proteins in close proximity in living cells

  • Compare to conventional immunoprecipitation results

• Microscopy-based interaction studies:

  • FRET or FLIM with fluorescently tagged proteins

  • Immunofluorescence co-localization analysis

  • Super-resolution microscopy to visualize nuclear speckles

• Functional validation of interactions:

  • Mutate potential interaction domains

  • Assess effects on splicing using minigene assays

  • Correlate interaction strength with splicing outcomes

These approaches provide complementary information about SRSF11's dynamic interactions within the spliceosome and other nuclear complexes.

How should I design experiments to study evolutionary conservation of SRSF11 function across species?

SRSF11 orthologs exist in multiple species, enabling evolutionary studies:

• Cross-species antibody validation:

  • Test reactivity against SRSF11 from mouse, rat, and other species

  • Verify specificity in each species with appropriate controls

  • Consider epitope conservation when selecting antibodies

• Comparative expression analysis:

  • Use validated antibodies to compare expression patterns across tissues

  • Assess subcellular localization conservation

  • Compare developmental expression timing

• Functional conservation studies:

  • Rescue experiments with orthologs in knockout systems

  • Compare binding preferences for RNA targets

  • Assess conservation of post-translational modification sites

• Data integration approaches:

  • Correlate protein conservation with functional importance

  • Identify species-specific SRSF11 features

  • Relate evolutionary changes to splicing pattern differences

These comparative approaches help identify core SRSF11 functions versus species-specific adaptations, providing insight into fundamental splicing mechanisms.

How can SRSF11 antibodies be integrated into high-throughput proteomics workflows?

SRSF11 antibodies can enhance proteomics studies through:

• Immunoaffinity enrichment:

  • Use SRSF11 antibodies conjugated to beads for targeted proteomics

  • Enrich for SRSF11-containing complexes before mass spectrometry

  • Identify low-abundance interactors missed in whole-proteome studies

• Reverse phase protein arrays (RPPA):

  • Analyze SRSF11 expression across many samples simultaneously

  • Quantify changes in response to various treatments

  • Correlate with other proteins in signaling networks

• Cellular barcoding approaches:

  • Combine with cellular indexing for proteomics studies

  • Profile SRSF11 expression/modification across heterogeneous populations

  • Correlate with cell state or phenotypic markers

• Single-cell proteomics integration:

  • Use SRSF11 antibodies in emerging single-cell proteomic techniques

  • Correlate with single-cell transcriptomics data

  • Map splicing factor dynamics at cellular resolution

These approaches extend the utility of SRSF11 antibodies beyond traditional applications into systems biology frameworks.

What considerations apply when using SRSF11 antibodies for live-cell imaging studies?

Live imaging of splicing factors presents unique challenges:

• Antibody format requirements:

  • Traditional antibodies cannot penetrate live cells

  • Consider using cell-permeable antibody fragments

  • Alternative approaches include fluorescently tagged nanobodies

• Genetic tagging alternatives:

  • Generate SRSF11-FP fusions (e.g., GFP, mCherry)

  • Validate that tags don't disrupt localization or function

  • Use CRISPR/Cas9 to tag endogenous SRSF11

• Experimental design considerations:

  • Minimize phototoxicity with appropriate imaging parameters

  • Use environmental chambers to maintain physiological conditions

  • Consider nuclear dynamics timescales when setting acquisition rates

• Analysis approaches:

  • Track nuclear speckle formation and dynamics

  • Measure SRSF11 mobility using FRAP or photoactivation

  • Correlate dynamics with cellular states or treatments

While challenging, live imaging provides unique insights into SRSF11 dynamics that cannot be obtained from fixed samples.

How can researchers address reproducibility challenges when using different SRSF11 antibody sources?

Variability between antibody sources can complicate research reproducibility:

• Standardization practices:

  • Maintain detailed records of antibody source, lot number, and dilution

  • Include validation data in publication methods sections

  • Consider antibody validation reporting guidelines (e.g., RRID identifiers)

• Cross-validation approaches:

  • Test multiple antibodies from different sources in parallel

  • Compare epitope specificity and performance

  • Validate key findings with orthogonal methods

• Recombinant antibody considerations:

  • Consider recombinant antibody technology for better reproducibility

  • Document antibody sequence when available

  • Evaluate monoclonal versus polyclonal trade-offs

• Community resources and repositories:

  • Share validation data through antibody validation databases

  • Consider contributing to community standards efforts

  • Use consistent positive controls across studies