P2RY13 Antibody

What are the key applications for P2RY13 antibodies in laboratory research?

P2RY13 antibodies have been validated for multiple experimental applications including Western blotting (WB), immunohistochemistry (IHC), immunofluorescence (IF), flow cytometry (FC), and enzyme-linked immunosorbent assay (ELISA). The recommended dilutions vary by application:

• Western blot: 1:200-1:2000

• Immunohistochemistry: 1:20-1:300

• Immunofluorescence: 1:200-1:1000

• Flow cytometry: 1:50-1:600

• ELISA: 1:20000

These applications allow researchers to detect and quantify P2RY13 expression at both protein and cellular levels across various experimental systems .

What is the typical molecular weight observed for P2RY13 in Western blot applications?

While the calculated molecular weight of P2RY13 is approximately 41 kDa (based on its 354 amino acid sequence), researchers typically observe a band at approximately 45 kDa in Western blot applications. This difference between calculated and observed molecular weight is likely due to post-translational modifications such as glycosylation or phosphorylation. Some researchers have reported higher molecular weight bands (up to 72 kDa) that may represent receptor oligomers or heavily modified forms of the protein .

Which species reactivity should be considered when selecting a P2RY13 antibody?

Most commercially available P2RY13 antibodies have been validated for reactivity with human samples. Many antibodies also cross-react with mouse and rat P2RY13, though this should be confirmed for each specific antibody. When working with non-human species, it's important to verify cross-reactivity, especially for monoclonal antibodies that may have more restricted epitope recognition. The highest sequence conservation tends to be in the intracellular loops and C-terminal regions of the receptor .

How should researchers validate the specificity of P2RY13 antibodies in their experimental systems?

To properly validate P2RY13 antibody specificity, implement these methodological approaches:

• Blocking peptide validation: Use the specific blocking peptide corresponding to the immunogen sequence. The blocking peptide binds and neutralizes the primary antibody, serving as a negative control to confirm specificity in Western blot and immunohistochemistry applications .

• Positive and negative controls: Include known P2RY13-expressing cells (HeLa, HepG2) as positive controls, and consider using P2RY13 knockout or knockdown systems as negative controls .

• Confirmation across multiple applications: Validate the antibody across multiple techniques (e.g., WB, IHC, and IF) to ensure consistent results .

• Recombinant expression system: Express recombinant P2RY13 in a cell line with low endogenous expression and compare with non-transfected cells as a specificity control .

These approaches collectively help ensure that the observed signals genuinely represent P2RY13 rather than non-specific binding or cross-reactivity .

What are the optimal tissue fixation and antigen retrieval methods for immunohistochemical detection of P2RY13?

For optimal immunohistochemical detection of P2RY13:

• Fixation: Paraformaldehyde (4% PFA) fixation has been successfully used for preserving P2RY13 antigenicity in tissue sections.

• Antigen retrieval options:

  • TE buffer (pH 9.0) is the primary recommended method for antigen retrieval

  • Alternatively, citrate buffer (pH 6.0) can be used if TE buffer yields suboptimal results

• Visualization systems: For low expression tissues, consider using high-sensitivity detection systems:

  • Universal Immuno-alkaline-phosphatase kit followed by New Fuchsin Substrate has been effectively used (resulting in red staining)

  • Hematoxylin counterstain provides good cellular context

• Positive control tissues: Human small intestine and mouse brain tissues have been validated as positive controls showing specific P2RY13 expression patterns .

These methodological considerations will significantly improve the signal-to-noise ratio in IHC applications targeting P2RY13.

How can researchers investigate P2RY13 function in inflammatory pathways using antibody-based approaches?

To investigate P2RY13's role in inflammatory pathways using antibody-based approaches:

• Co-immunoprecipitation (Co-IP) studies: Use P2RY13 antibodies to pull down the receptor and identify binding partners within inflammatory signaling complexes. This approach can reveal direct interactions with components of the IL-6/STAT3 pathway, which has been implicated in P2RY13-mediated inflammation .

• Phospho-specific Western blot analysis: Combine P2RY13 activation or inhibition experiments with phospho-specific antibodies against STAT3 (pY705) to monitor pathway activation. This dual-antibody approach allows correlation between P2RY13 expression/activity and downstream signaling events .

• Chromatin immunoprecipitation (ChIP) assays: After stimulating P2RY13, use antibodies against transcription factors like phospho-STAT3 to identify inflammatory genes directly regulated by P2RY13 signaling.

• Proximity ligation assay (PLA): Employ P2RY13 antibodies together with antibodies against inflammatory pathway components to visualize direct molecular interactions in situ with subcellular resolution.

These combined antibody approaches can help elucidate the mechanisms by which P2RY13 influences intestinal inflammation through IL-6/STAT3 signaling, as observed in models of ulcerative colitis .

What methodological considerations are important when using P2RY13 antibodies to study receptor trafficking and internalization?

When investigating P2RY13 trafficking and internalization:

• Live-cell immunofluorescence:

  • Use non-permeabilizing conditions with antibodies recognizing extracellular epitopes to specifically label surface receptors

  • Track internalization by monitoring the disappearance of surface staining after agonist stimulation (e.g., with ADP)

• Surface biotinylation assays:

  • Combine with P2RY13 antibodies in Western blot to quantitatively measure receptor internalization rates

  • Include controls with receptor antagonists (such as MRS2211) to confirm specificity of internalization

• Subcellular fractionation:

  • Use P2RY13 antibodies to detect receptor distribution across membrane, endosomal, and lysosomal fractions

  • Requires careful validation of fraction purity with compartment-specific markers

• Antibody feeding assays:

  • Label surface receptors with antibodies at 4°C

  • Allow internalization at 37°C

  • Use differential staining of remaining surface vs. internalized antibodies to track trafficking

• Co-localization studies:

  • Combine P2RY13 antibodies with markers for clathrin, caveolin, or endosomal compartments

  • Use high-resolution confocal or super-resolution microscopy for detailed trafficking pathways

These approaches enable quantitative assessment of how P2RY13 transitions between cellular compartments in response to agonist stimulation or during signaling events.

How can researchers utilize P2RY13 antibodies to investigate its role as a biomarker in pathological conditions?

To investigate P2RY13 as a biomarker in pathological conditions:

• Tissue microarray (TMA) analysis:

  • Optimize P2RY13 antibody staining protocols using established positive controls (small intestine, brain tissue)

  • Develop standardized scoring systems (e.g., H-score, intensity × percentage positive cells)

  • Analyze correlation with clinicopathological variables and survival outcomes

• Multiplex immunohistochemistry/immunofluorescence:

  • Combine P2RY13 antibodies with markers for specific cell types and activation states

  • In renal clear cell carcinoma studies, co-stain with immune cell markers to assess correlation with immune infiltration patterns

  • Use image analysis software for quantitative assessment of co-localization and expression levels

• Liquid biopsy development:

  • Develop sensitive ELISA or multiplexed bead-based assays using P2RY13 antibodies to detect shed receptor in patient fluids

  • Validate in longitudinal patient cohorts with appropriate controls

• Cross-platform validation:

  • Correlate antibody-based protein detection with RNA-seq or qPCR data for P2RY13 mRNA expression

  • Use bioinformatic approaches to integrate protein expression data with public datasets (e.g., TCGA, GEO) for broader contextual understanding

These methodological approaches can help establish P2RY13 as a clinically relevant biomarker in conditions like ulcerative colitis or renal clear cell carcinoma, where its expression patterns have already shown diagnostic and prognostic potential .

What strategies can resolve non-specific binding issues when using P2RY13 antibodies?

To resolve non-specific binding issues with P2RY13 antibodies:

• Optimized blocking protocols:

  • Test different blocking agents (BSA, normal serum, commercial blockers)

  • For Western blots, 5% non-fat dry milk in TBST or 3-5% BSA has shown effective results

  • For IHC/IF, 3% BSA with extended blocking times (30+ minutes) can reduce background

• Antibody titration:

  • Perform systematic dilution series to identify optimal concentration

  • Start with manufacturer's recommended range (e.g., 1:200-1:2000 for WB), then refine

  • For low expression tissues, higher concentrations may be necessary, but with enhanced blocking

• Validation with blocking peptides:

  • Use specific blocking peptides corresponding to the immunogen

  • Preincubate antibody with excess peptide before application to sample

  • This approach effectively identifies non-specific binding components of the signal

• Secondary antibody controls:

  • Include controls omitting primary antibody but retaining secondary antibody

  • Test alternative secondary antibodies if background persists

• Sample preparation optimization:

  • For Western blots, ensure complete denaturation and robust washing steps

  • For IHC, optimize fixation time and antigen retrieval conditions

  • For IF, test different permeabilization methods and durations

These methodological refinements can significantly improve signal-to-noise ratio when working with P2RY13 antibodies.

How can researchers address discrepancies in observed molecular weights of P2RY13 across different experimental systems?

To address molecular weight discrepancies when detecting P2RY13:

• Post-translational modifications assessment:

  • The calculated molecular weight of P2RY13 is ~41 kDa, but observed weights range from 45-72 kDa

  • Use glycosylation inhibitors (tunicamycin, PNGase F) to assess contribution of N-linked glycosylation

  • Phosphatase treatment can determine if phosphorylation contributes to weight shifts

• Sample preparation variables:

  • Test both reducing and non-reducing conditions

  • Compare different lysis buffers (RIPA vs. gentler NP-40 based buffers)

  • Evaluate effects of different detergents on apparent molecular weight

• Receptor oligomerization analysis:

  • Higher molecular weight bands (e.g., 72 kDa) may represent receptor dimers or oligomers

  • Use crosslinking agents to stabilize potential oligomeric forms

  • Compare native vs. denaturing gel systems to preserve protein-protein interactions

• Technical validation across systems:

  • When comparing different cell types or tissues, run samples side-by-side

  • Include recombinant protein standards with known molecular weight

  • Test multiple antibodies targeting different epitopes to confirm identity of bands

• Antibody specificity confirmation:

  • Use siRNA knockdown to confirm specificity of each observed band

  • Compare band patterns in overexpression systems vs. endogenous expression

  • Blocking peptide controls can help identify which bands represent specific binding

These approaches provide a systematic framework to determine the true identity of P2RY13 bands across different experimental systems and conditions.

What methodological approaches can researchers use to study P2RY13 interactions with other purinergic receptors?

To investigate P2RY13 interactions with other purinergic receptors:

• Co-immunoprecipitation with dual antibody detection:

  • Use P2RY13 antibodies to immunoprecipitate receptor complexes

  • Probe with antibodies against other purinergic receptors (especially P2Y12, which shares ~45% sequence identity)

  • Include appropriate controls with individual receptor overexpression

• Bioluminescence/Förster resonance energy transfer (BRET/FRET):

  • Generate fusion constructs of P2RY13 and other purinergic receptors with compatible BRET/FRET pairs

  • Use antibodies to confirm expression levels and proper localization

  • Measure energy transfer to detect close molecular associations

• Proximity ligation assay (PLA):

  • Combine P2RY13 antibodies with antibodies against other purinergic receptors

  • This technique allows visualization of proteins that are within 40nm of each other

  • Quantify PLA signals in different subcellular compartments to map interaction domains

• Bimolecular fluorescence complementation (BiFC):

  • Verify construct expression using epitope-specific antibodies

  • Correlate BiFC signals with antibody-detected expression levels

• Sequential immunoprecipitation:

  • First immunoprecipitate with anti-P2RY13

  • Elute and perform second immunoprecipitation with antibodies against potential partner receptors

  • This approach helps identify specific receptor hetero-oligomers

These methodologies can help elucidate how P2RY13 functions within the broader purinergic receptor family, particularly its functional relationship with the structurally similar P2Y12 receptor .

How can researchers combine P2RY13 antibodies with functional assays to correlate receptor expression with cellular responses?

To correlate P2RY13 expression with functional responses:

• Single-cell immunostaining with calcium imaging:

  • Perform calcium flux assays in response to ADP stimulation (with/without P2Y12 inhibitors)

  • Fix and immunostain the same cells for P2RY13

  • Correlate receptor expression level with magnitude of calcium response

  • Include MRS2211 (P2RY13 antagonist) to confirm specificity of response

• Flow cytometry with functional readouts:

  • Use P2RY13 antibodies to quantify receptor expression levels

  • Simultaneously measure functional responses (e.g., phospho-STAT3) in the same cells

  • Sort cells based on receptor expression level and assess functional differences

• Stable cell lines with variable expression:

  • Create cell lines with controlled P2RY13 expression levels

  • Validate expression using carefully titrated antibody staining

  • Measure IL-6 production, STAT3 phosphorylation, and other functional outcomes

  • Perform dose-response curves with agonists/antagonists at each expression level

• Tissue section analysis:

  • Perform IHC for P2RY13 on serial sections

  • Stain adjacent sections for functional markers (phospho-STAT3, IL-6, tight junction proteins)

  • Correlate expression patterns across serial sections

  • This approach is particularly valuable for intestinal inflammation studies

• In vivo validation:

  • Use P2RY13 antibodies to quantify receptor expression in animal models

  • Correlate with disease severity metrics and treatment responses

  • Include tissue-specific knockout models as controls

These approaches enable direct correlation between P2RY13 expression levels and functional outcomes, particularly in the context of inflammatory signaling through the IL-6/STAT3 pathway.

What methodologies are available for studying P2RY13's role in cholesterol transport and metabolism using antibody-based approaches?

To investigate P2RY13's role in cholesterol transport and metabolism:

• Co-localization with cholesterol transport markers:

  • Use P2RY13 antibodies with markers for HDL receptors, caveolae, and lipid rafts

  • Apply super-resolution microscopy techniques to define spatial relationships

  • Track changes in localization patterns after ADP stimulation

• Immunoprecipitation with lipid analysis:

  • Use P2RY13 antibodies to immunoprecipitate receptor complexes

  • Analyze associated lipids by mass spectrometry

  • Compare lipid profiles between basal and stimulated conditions

• Proximity labeling approaches:

  • Create P2RY13 fusion constructs with proximity labeling enzymes (BioID, APEX)

  • Validate construct expression and function using P2RY13 antibodies

  • Identify proximal proteins involved in hepatic HDL endocytosis

• Tissue-specific expression analysis:

  • Use P2RY13 antibodies to quantify expression in liver sections from various metabolic conditions

  • Correlate with markers of cholesterol transport and hepatic lipid content

  • Compare expression in models of dyslipidemia versus controls

• In vitro functional reconstitution:

  • Reconstitute P2RY13-dependent HDL endocytosis in cell models

  • Use antibodies to confirm expression levels and localization

  • Measure cholesterol uptake and efflux in relation to receptor expression

These methodologies provide a comprehensive approach to understanding how P2RY13 contributes to cholesterol metabolism, particularly in the context of hepatic HDL endocytosis, as suggested by previous research .

How can researchers apply P2RY13 antibodies in multiplexed imaging approaches to study tissue-specific expression patterns?

For multiplexed imaging of P2RY13 expression patterns:

• Multiplex immunofluorescence protocols:

  • Combine P2RY13 antibodies with markers for specific cell types

  • For brain tissue: include neuronal, glial, and endothelial markers

  • For immune tissues: combine with markers for specific immune cell subsets

  • Use spectral unmixing to resolve multiple fluorophores

• Cyclic immunofluorescence (CycIF):

  • Perform sequential rounds of staining, imaging, and antibody stripping

  • Include P2RY13 antibodies in appropriate rounds

  • This approach allows combination with 20+ additional markers on the same section

  • Critical for mapping receptor expression across complex tissue ecosystems

• Mass cytometry imaging (IMC):

  • Conjugate P2RY13 antibodies with rare earth metals

  • Combine with metal-conjugated antibodies against cell type markers

  • Achieve high-parameter imaging (30+ markers) with subcellular resolution

  • Particularly valuable for immune cell profiling in inflammatory conditions

• RNA-protein co-detection:

  • Combine P2RY13 antibody staining with RNAscope in situ hybridization

  • Correlate protein expression with mRNA levels at single-cell resolution

  • Identify potential post-transcriptional regulation mechanisms

• Spatial transcriptomics integration:

  • Perform P2RY13 IHC on serial sections adjacent to spatial transcriptomics slides

  • Register images and correlate protein expression with transcriptional programs

  • This approach provides contextualized understanding of receptor function

These advanced imaging approaches enable detailed mapping of P2RY13 expression across different tissue compartments and cell types, providing important context for functional studies of this receptor in complex biological systems .

Table 1: Comparative Analysis of P2RY13 Antibody Applications