The PURA Antibody, HRP conjugated is a bioconjugate designed for enzymatic detection in immunoassays. It combines a rabbit polyclonal antibody targeting purine-rich element binding protein A (PURA) with horseradish peroxidase (HRP), enabling colorimetric or chemiluminescent signal amplification. PURA is a 35–40 kDa protein involved in RNA metabolism and chromatin remodeling, making it a critical target in studies of neurodevelopment, cancer, and RNA-binding processes .
HRP conjugation to antibodies typically employs heterobifunctional crosslinkers to form stable bonds. Below are methodologies relevant to PURA-antibody conjugation:
HRP Activity: >200 U/mg, high-quality maleimide-activated HRP .
Conjugation Efficiency: Target 2–4 HRP molecules per antibody .
A modified protocol involving lyophilized activated HRP demonstrated superior performance:
Antibody Titer: 1:5000 (vs. 1:25 for classical methods), with p < 0.001 .
Mechanism: Lyophilization reduces reaction volume, increasing collision frequency between HRP and antibody molecules, per collision theory .
The PURA Antibody, HRP conjugated is optimized for:
Reactivity: Human, mouse, rat samples .
| Parameter | Value | Source |
|---|---|---|
| Host/Isotype | Rabbit polyclonal IgG | |
| Immunogen | PURA fusion protein (Ag12173) | |
| MW | 35–40 kDa (observed) | |
| Storage | -20°C (PBS, 50% glycerol, 0.02% sodium azide) |
PURA (Purine-rich single-stranded DNA-binding protein alpha, also known as PUR1) functions as a transcription activator that specifically binds to the purine-rich single strand of the PUR element located upstream of the MYC gene. This protein plays essential roles in DNA replication initiation and recombination processes, making it an important target for various molecular biology studies . PURA interacts with critical cellular components including retinoblastoma protein and RNA polymerase II, which contributes to its pivotal role in regulating cell division and DNA transcription . The protein's involvement in these fundamental cellular processes makes PURA antibodies valuable tools for investigating transcriptional regulation, cell cycle control, and related pathways.
HRP (horseradish peroxidase) conjugation to antibodies involves the chemical linking of HRP enzyme molecules to antibody proteins to create detection reagents for immunoassays. The conjugation process typically utilizes heterobifunctional cross-linkers to covalently link antibodies to HRP while maintaining antibody affinity and providing a functional reporter for antigen detection . One common approach employs Sulfo-SMCC to generate maleimide-activated HRP that reacts with sulfhydryl groups created in antibodies through SATA-mediated thiolation . This creates a stable thioether linkage between the antibody and HRP, resulting in a conjugate that can catalyze chromogenic or chemiluminescent reactions when exposed to appropriate substrates, enabling visual or quantitative detection of target antigens in various immunoassay formats.
PURA Antibody with HRP conjugation is primarily utilized in ELISA (Enzyme-Linked Immunosorbent Assay) applications as indicated by product specifications . Additionally, while not explicitly stated for the PURA Antibody specifically, HRP-conjugated antibodies are generally valuable for various immunological techniques including Western blotting, immunohistochemistry, and other immunodetection methods . The conjugation provides a direct detection system that eliminates the need for secondary antibody incubation steps, potentially reducing background noise and increasing assay specificity. These conjugates are particularly useful when investigating the expression, localization, and interactions of PURA protein in diverse experimental contexts, ranging from cell culture studies to tissue analysis.
Optimizing dilution of PURA Antibody, HRP conjugated for ELISA requires a systematic titration approach. Begin with manufacturer's recommended dilution range (typically 1:500-1:5000 for antibody working solutions) . Perform a checkerboard titration by preparing serial dilutions of both the antibody and your target antigen. For each dilution, evaluate signal-to-noise ratio by comparing specific signal against background readings from negative controls. The optimal dilution should provide maximum signal with minimal background interference.
Consider these methodological steps:
Prepare serial dilutions of the PURA Antibody-HRP (e.g., 1:500, 1:1000, 1:2000, 1:5000)
For each antibody dilution, test against varying antigen concentrations
Include proper controls: blank wells (no antigen, no antibody), negative controls (no antigen, with antibody), and positive controls
Analyze data to identify the dilution providing optimal detection sensitivity while maintaining low background
Utilize a stabilizing diluent such as HRP Conjugate Stock Stabilizer (diluted to 1X working concentration) to maintain conjugate integrity during the optimization process
This methodical approach ensures reliable and reproducible results for your specific experimental conditions.
For optimal storage and dilution of PURA Antibody, HRP conjugated, specialized buffer systems are recommended to maintain both antibody specificity and HRP enzymatic activity. A key consideration is using HRP Conjugate Stock Stabilizer, which when diluted to its 1X working concentration, helps preserve the functional integrity of both the HRP enzyme and immunoglobulin components . This proprietary formulation maintains the native three-dimensional conjugate structure during storage while enhancing the interaction between the IgG component and target antigen .
For dilution purposes:
Add 1 part HRP Conjugate Stock Stabilizer (5X) to 4 parts deionized water and mix thoroughly for 5-15 minutes
Add the PURA antibody-HRP conjugate directly into this diluent to achieve your working dilution
Mix gently for 5-15 minutes to ensure homogeneous distribution
For storage:
Store protected from light at 2-8°C
1X working dilutions can be stored at 2-8°C when protected from light
Maintain pH between 6.5-7.5, as maleimide conjugation linkages remain stable in this range and are minimally susceptible to hydrolysis
Avoid repeated freeze-thaw cycles which can compromise both antibody binding and HRP activity
These buffer conditions help prevent contamination issues and extend the functional utility of the conjugate while inhibiting non-specific binding to plate coating proteins .
Verification of successful HRP conjugation to PURA antibody can be achieved through multiple analytical approaches. One recommended method involves determining the HRP to protein ratio using spectrophotometric measurements . This process typically includes:
Measure absorbance at 280 nm (A280) for protein concentration and at 403 nm (A403) for HRP determination
Calculate the molar ratio using extinction coefficients (ε280 for antibody and ε403 for HRP)
Optimal conjugates typically have 2-4 HRP molecules per antibody
Functional verification can be performed by:
Running a Western blot with known PURA-expressing samples (e.g., human brain tissue lysate)
Comparing signal intensity between the conjugated antibody and a traditional primary-secondary antibody detection system
Evaluating specificity through appropriate controls (including competing peptides or knockout samples)
Additionally, ELISA-based functionality tests provide further confirmation:
Coat plate with target antigen or use a sandwich approach with capture antibody
Add serial dilutions of the HRP-conjugated PURA antibody
Develop with appropriate substrate (e.g., TMB)
Compare results to standard curves generated with known functioning HRP-conjugated antibodies
This multi-faceted verification approach ensures both the chemical success of the conjugation and the functional integrity of the final reagent.
Investigating PURA's role in transcriptional regulation using HRP-conjugated PURA antibody requires sophisticated experimental designs that leverage the direct detection capabilities of this conjugate. PURA is known to specifically bind the purine-rich single strand of the PUR element located upstream of the MYC gene and may function as a transcription activator . To elucidate its regulatory mechanisms:
Chromatin Immunoprecipitation (ChIP) with direct detection:
Crosslink protein-DNA interactions in cells of interest
Sonicate chromatin to appropriate fragment sizes
Immunoprecipitate with PURA Antibody, HRP conjugated
Detect bound complexes directly using chemiluminescence substrates
Elute and analyze DNA fragments through qPCR or sequencing to identify binding regions
Transcription factor ELISA:
Immobilize oligonucleotides containing putative PURA binding sequences
Incubate with nuclear extracts
Detect bound PURA using the HRP-conjugated antibody
Quantify binding through colorimetric or chemiluminescent readout
Co-regulatory protein interaction studies:
Immunoprecipitate retinoblastoma protein or RNA polymerase II
Detect co-precipitated PURA using the HRP-conjugated antibody in Western blot format
Alternatively, develop sandwich ELISA systems to quantify these interactions
These approaches provide direct insights into PURA's DNA binding patterns, transcriptional targets, and co-regulatory protein networks, expanding our understanding of its role in transcriptional regulation.
When employing PURA Antibody, HRP conjugated in multiplex immunoassays, researchers must navigate several technical challenges. The primary complexities arise from potential cross-reactivity issues and signal interference between detection systems.
Key pitfalls and mitigation strategies include:
Cross-reactivity concerns:
PURA antibodies may exhibit varying degrees of cross-reactivity with homologous proteins
Problem: False positive signals that compromise assay specificity
Solution: Perform extensive validation with appropriate controls including knockout/knockdown samples and competing peptides
HRP substrate compatibility in multiplex settings:
Problem: Substrate diffusion between detection zones can create signal bleeding
Solution: Optimize spatial separation between detection areas and consider sequential substrate addition protocols
Signal magnitude discrepancies:
PURA detection may produce signals of significantly different intensity compared to other targets
Problem: Dominant signals can mask weaker ones when using shared detection systems
Solution: Carefully balance antibody concentrations and utilize signal normalization algorithms during data analysis
HRP inactivation by sample components:
Molecular weight considerations:
PURA has potential phosphorylation sites which may explain its migration at a higher molecular weight than predicted (approximately 42 kDa versus the predicted 35 kDa)
Problem: This variability can complicate multiplexed analysis
Solution: Include molecular weight markers and conduct thorough validation studies
By anticipating these challenges and implementing appropriate controls and optimization strategies, researchers can maximize the reliability of multiplex immunoassays involving PURA Antibody, HRP conjugated.
PURA protein often presents unexpected molecular weight patterns in immunodetection experiments, which can complicate result interpretation. The predicted molecular weight of PURA is approximately 35 kDa, but it frequently migrates at a higher molecular weight around 42 kDa . This discrepancy requires systematic troubleshooting approaches:
Understanding post-translational modifications:
Sample preparation considerations:
Evaluate different lysis buffers and their effects on PURA detection
Test various reducing agent concentrations to ensure complete protein denaturation
Optimize heating conditions (temperature and duration) to prevent aggregation or degradation
Gel system optimization:
Compare different polyacrylamide percentages to improve resolution in the 35-45 kDa range
Evaluate gradient gels versus fixed percentage gels
Consider native versus denaturing conditions to assess multimerization
Antibody specificity verification:
Perform peptide competition assays to confirm signal specificity
Compare detection patterns across multiple tissue types with known PURA expression levels
Include recombinant PURA protein as a positive control
Detection system troubleshooting:
Optimize substrate incubation time when using the HRP-conjugated antibody
Compare different HRP substrates for optimal signal-to-noise ratio
Consider signal enhancement systems if sensitivity is limiting
By methodically addressing these factors, researchers can accurately interpret PURA detection results despite its non-standard migration pattern in electrophoretic analyses.
Sensitivity comparison:
| Detection Parameter | PURA Antibody, HRP Conjugated | Two-Step Detection Method |
|---|---|---|
| Detection limit | Typically higher (less sensitive) | Often lower (more sensitive) |
| Signal amplification | None - 1:1 binding ratio | Significant - multiple secondary antibodies can bind each primary |
| Background noise | Generally lower | Potentially higher due to secondary antibody cross-reactivity |
| Time efficiency | Faster (single incubation) | Slower (two separate incubations) |
| Protocol complexity | Simpler | More complex |
| Sample consumption | Lower | Higher |
To optimize results with HRP-conjugated PURA antibody:
Use specialized HRP Conjugate Stock Stabilizer to maintain conjugate integrity
Extend substrate incubation time to enhance signal development
Consider signal enhancement systems for critical low-abundance applications
Optimize blocking conditions to improve signal-to-noise ratio
The choice between these approaches should be guided by experimental requirements, with direct conjugates favored for routine detection and two-step methods reserved for applications requiring maximum sensitivity.
Optimized protocols for PURA Antibody, HRP conjugated vary based on the experimental system. Here are tailored methodologies for three common research applications:
ELISA Protocol:
Coating: Adsorb capture antibody or antigen to microplate (100 μL/well, overnight at 4°C)
Blocking: 200 μL/well blocking buffer (typically 1-5% BSA in PBS), 1-2 hours at room temperature
Sample addition: Add diluted samples and standards (100 μL/well), incubate 1-2 hours at room temperature
Detection: Add PURA Antibody, HRP conjugated diluted in HRP Conjugate Stock Stabilizer (1X working concentration) at recommended dilution (1:500-1:5000) , incubate 1 hour at room temperature
Development: Add 100 μL/well TMB substrate, monitor color development (typically 5-30 minutes)
Stop reaction: Add 100 μL/well stop solution (usually 2N H₂SO₄)
Read: Measure absorbance at 450 nm with 570 nm reference wavelength
Western Blot Protocol:
Protein separation: Load 10-30 μg total protein per lane on appropriate percentage SDS-PAGE gel
Blocking: Incubate membrane in 5% non-fat dry milk or 3% BSA in TBST for 1 hour at room temperature
Primary detection: Add PURA Antibody, HRP conjugated diluted in blocking buffer (1:500-1:5000) , incubate overnight at 4°C
Washing: Wash membrane 3-5 times with TBST, 5 minutes each
Development: Apply chemiluminescent substrate compatible with HRP (such as Azure Radiance ECL) and detect signal
Immunocytochemistry Protocol:
Fixation: Fix cells with 4% paraformaldehyde, 15 minutes at room temperature
Permeabilization: 0.1-0.5% Triton X-100 in PBS, 10 minutes at room temperature
Blocking: 5% normal serum in PBS, 1 hour at room temperature
Detection: Apply diluted PURA Antibody, HRP conjugated (1:500-1:1000) in blocking buffer, incubate overnight at 4°C
Washing: Wash 3-5 times with PBS, 5 minutes each
Substrate: Apply DAB or other peroxidase substrate
Counterstain: Optional hematoxylin nuclear counterstain
Mounting: Mount with appropriate medium and visualize
Each protocol should be optimized based on specific sample types, target abundance, and experimental goals.
Maximizing the shelf life and activity of PURA Antibody, HRP conjugated requires careful attention to storage conditions, handling practices, and stabilization chemistry. The following comprehensive approach integrates best practices from multiple sources:
Optimal Storage Conditions:
Temperature management:
Store concentrated stock at 2-8°C, never freeze HRP conjugates unless specifically recommended by manufacturer
Avoid temperature fluctuations which can accelerate protein denaturation and enzyme inactivation
For long-term storage (>1 month), aliquot to minimize freeze-thaw cycles
Buffer composition:
Use HRP Conjugate Stock Stabilizer diluted to its 1X working concentration for dilution and storage
This specialized formulation maintains the functional integrity of both the HRP enzyme and immunoglobulin components
Ensure pH remains between 6.5-7.5, as maleimide linkages are most stable in this range
Protection from destabilizing factors:
Usage Recommendations:
Prepare working dilutions just before use when possible
If working dilutions must be stored, maintain them at 2-8°C protected from light
When removing from storage, allow solutions to equilibrate to room temperature before opening to prevent condensation
Use only clean, protein-low binding tubes and pipette tips for handling
Avoid introducing bubbles which can denature proteins at air-liquid interfaces
By implementing these evidence-based practices, researchers can significantly extend the usable lifetime of PURA Antibody, HRP conjugated preparations, ensuring consistent performance across experiments and reducing reagent costs.
Investigating PURA's interactions with retinoblastoma protein and RNA polymerase II using HRP-conjugated PURA antibody enables direct visualization of these critical protein complexes. These interactions are fundamental to PURA's role in cell division and DNA transcription . Several advanced methodological approaches can be employed:
Proximity Ligation Assay (PLA) with direct detection:
Fix and permeabilize cells expressing PURA, retinoblastoma protein, and RNA polymerase II
Incubate with PURA Antibody, HRP conjugated and antibodies against interaction partners (conjugated to complementary oligonucleotides)
Perform ligation and rolling circle amplification
Visualize interaction signals through direct HRP-mediated chromogenic or chemiluminescent detection
This approach allows visualization of endogenous protein interactions with high specificity and sensitivity
Co-immunoprecipitation with direct detection:
Prepare cell/tissue lysates under non-denaturing conditions
Immunoprecipitate retinoblastoma protein or RNA polymerase II
Resolve proteins by SDS-PAGE and transfer to membrane
Detect co-precipitated PURA directly using HRP-conjugated PURA antibody
This streamlined approach eliminates secondary antibody incubation steps and reduces background
Chromatin Immunoprecipitation-reChIP:
Perform sequential ChIP using antibodies against retinoblastoma protein or RNA polymerase II followed by PURA Antibody, HRP conjugated
Utilize HRP activity for direct elution through substrate-mediated release
Analyze recovered DNA sequences to identify genomic regions where PURA co-localizes with its interaction partners
This technique identifies specific genomic contexts where these protein interactions occur
These methodologies provide complementary insights into the molecular mechanisms through which PURA exerts its regulatory functions in transcription and cell cycle control, with the HRP conjugation enabling direct detection with reduced background interference.
Recent advances in super-resolution microscopy techniques have expanded the utility of HRP-conjugated antibodies, including PURA Antibody, HRP conjugated, beyond traditional applications. These developments leverage the catalytic activity of HRP to generate localized precipitates or fluorescent products that can be detected with nanoscale precision.
Emerging techniques include:
APEX/HRP-mediated proximity labeling for correlative light-electron microscopy:
HRP-conjugated antibodies catalyze the local deposition of DAB (3,3'-diaminobenzidine) in the presence of H₂O₂
The resulting precipitate can be detected by both light microscopy and electron microscopy
This approach enables visualization of PURA localization at ultrastructural resolution
Particularly valuable for studying nuclear subdomains where PURA functions in transcription regulation
CLEM (Correlative Light and Electron Microscopy) with HRP enhancement:
HRP-conjugated PURA antibody catalyzes the deposition of electron-dense precipitates
These precipitates provide contrast in electron microscopy while maintaining compatibility with fluorescence detection
Enables correlation between PURA's dynamic behavior (from light microscopy) and its precise subcellular localization (from electron microscopy)
HRP-CLARITY for 3D tissue imaging:
HRP-conjugated antibodies are used with CLARITY-processed tissues
The catalytic activity generates fluorescent products that can be imaged in three dimensions
Allows mapping of PURA distribution across complex tissue architectures with cellular resolution
Particularly valuable for studying PURA's role in neural tissues where its function is highly relevant
Single-molecule HRP amplification systems:
Utilizes the catalytic cycle of HRP to generate thousands of fluorescent molecules per antibody
Enables detection of low-abundance PURA molecules that would otherwise be below detection threshold
Can be combined with photoactivation techniques for sequential detection in multiplexed imaging
These methodological advances extend the capabilities of HRP-conjugated antibodies beyond traditional biochemical assays into the realm of high-resolution spatial analysis, offering new insights into PURA's subcellular distribution and functional interactions.
Optimizing the bioconjugation process for creating custom PURA Antibody, HRP conjugates requires precise control over multiple parameters to achieve optimal conjugate performance. This comprehensive approach draws on established bioconjugation principles applicable to PURA and other target antibodies.
Critical optimization parameters include:
Selection of conjugation chemistry:
Heterobifunctional cross-linkers like Sulfo-SMCC are recommended for generating maleimide-activated HRP that reacts with sulfhydryl groups on antibodies
Alternative consideration: For PURA antibodies with limited available lysines, periodate oxidation of HRP glycosyl groups can be used to generate aldehyde groups that react with primary amines
Antibody preparation:
Thiolation using SATA (N-Succinimidyl S-Acetylthioacetate) introduces controlled numbers of sulfhydryl groups
Antibody:SATA molar ratios should be optimized (typically 1:5 to 1:20) to achieve desired conjugation levels
Buffer exchange into conjugation buffer (typically pH 6.5-7.5 phosphate buffer) using desalting columns
Optimization of HRP:antibody ratio:
Test multiple molar ratios (typically 2:1 to 10:1 HRP:antibody)
Balance between:
Too few HRP molecules = insufficient sensitivity
Too many HRP molecules = potential loss of antibody binding capacity
Evaluate conjugate performance across ratio range to identify optimal formulation
Reaction conditions:
Temperature: Generally performed at room temperature (20-25°C)
Duration: Typically 2-4 hours, optimize by testing multiple timepoints
pH: Maintain between 6.5-7.5 to ensure maleimide stability while preserving antibody function
Protect from light during conjugation to prevent photooxidation of the heme group
Purification strategy:
Size exclusion chromatography to separate conjugates from unreacted components
Consider affinity purification to select for functional conjugates
Avoid harsh conditions that might compromise HRP activity
Stabilization of final conjugate:
By systematically optimizing these parameters, researchers can develop PURA Antibody, HRP conjugates with optimal sensitivity, specificity, and stability for their specific research applications.
PURA protein has significant implications in neuroscience research, with emerging applications for PURA Antibody, HRP conjugated reflecting this importance. The protein's role in DNA replication and transcriptional regulation has direct relevance to neuronal development and function, opening several innovative research avenues.
Emerging applications include:
Investigation of PURA in neurodevelopmental disorders:
PURA mutations are associated with neurodevelopmental conditions
HRP-conjugated antibodies enable direct visualization of PURA distribution in neural tissues
Applications in both animal models and patient-derived samples provide insights into pathological mechanisms
Direct detection with reduced background interference is particularly valuable in heterogeneous neural tissues
Single-cell analysis of PURA expression patterns:
Combining HRP-conjugated PURA antibodies with microfluidic systems
Enables high-throughput screening of PURA expression across neural cell populations
HRP signal amplification provides sensitivity needed for detecting subtle expression differences
Correlation with cell type-specific markers reveals functional specialization
Activity-dependent PURA regulation studies:
HRP-conjugated antibodies in time-resolved detection systems
Monitoring PURA localization changes in response to neuronal activation
Investigation of PURA's role in activity-dependent gene expression
Potential insights into learning and memory mechanisms
PURA in neuroinflammatory processes:
Examination of PURA regulation in glial cells during inflammatory responses
HRP-mediated detection in complex tissue microenvironments
Potential implications for neurodegenerative and neuroinflammatory conditions
Integration with multiplex detection systems to analyze PURA in conjunction with inflammatory markers
These emerging applications harness the direct detection capabilities of HRP-conjugated PURA antibodies to illuminate the protein's complex roles in neural function, with significant implications for understanding both normal neurodevelopment and neurological disorders.
Integration of PURA Antibody, HRP conjugated into high-throughput screening (HTS) platforms enables rapid, sensitive detection of PURA protein across large sample sets. This integration requires careful consideration of assay design, automation compatibility, and data analysis methodologies.
Key integration strategies include:
Microplate-based ELISA adaptation:
Optimize PURA Antibody, HRP conjugated concentration (1:500-1:5000) for maximum signal-to-noise ratio
Implement automated liquid handling systems for consistent reagent dispensing
Standardize plate washing parameters to minimize well-to-well variability
Develop quality control metrics including Z-factor calculation for assay validation
HRP Conjugate Stock Stabilizer can improve consistency by maintaining conjugate integrity across screening runs
Multiplex bead-based assays:
Couple capture antibodies against PURA to spectrally distinct microbeads
Detect bound PURA with HRP-conjugated PURA antibodies (for sandwich format)
Utilize flow cytometry or dedicated bead analyzers for high-throughput readout
Enable simultaneous analysis of PURA alongside other proteins of interest
Automated Western blotting platforms:
Implement PURA Antibody, HRP conjugated in capillary-based automated Western systems
Optimize antibody concentration and incubation conditions for these specialized platforms
Account for the observed higher molecular weight migration pattern of PURA (approximately 42 kDa instead of predicted 35 kDa)
Enable quantitative comparison across large sample sets
High-content screening integration:
Utilize PURA Antibody, HRP conjugated with precipitating substrates for cellular imaging
Implement automated microscopy with standardized image acquisition settings
Develop image analysis algorithms to quantify PURA expression, localization, and co-localization patterns
Enable multiparametric analysis correlating PURA with cellular phenotypes
Data management and analysis pipeline:
Implement laboratory information management systems (LIMS) to track samples and assay conditions
Develop standardized data processing workflows for consistent analysis
Incorporate machine learning approaches for pattern recognition in complex datasets
Enable integration with other -omics datasets for comprehensive analysis