pi071 Antibody

What is pi071 Antibody and what organism does it target?

Pi071 Antibody is a rabbit polyclonal antibody that specifically recognizes the pi071 protein (UniProt: O42997) encoded by the SPBC27B12.07 gene in Schizosaccharomyces pombe (fission yeast). The antibody is generated using a recombinant Schizosaccharomyces pombe protein as the immunogen, specifically from strain 972 / ATCC 24843. This antibody has been affinity-purified to enhance specificity for the target protein. As a polyclonal antibody, it recognizes multiple epitopes on the target protein, which can provide robust detection in various experimental conditions. The antibody's specificity for yeast targets makes it particularly valuable for researchers studying S. pombe cellular processes and protein functions .

What applications is pi071 Antibody validated for?

Pi071 Antibody has been validated for two primary applications: Western Blot (WB) and Enzyme-Linked Immunosorbent Assay (ELISA). In Western blotting applications, the antibody can detect denatured pi071 protein from yeast lysates, allowing researchers to assess protein expression levels and molecular weight. For ELISA applications, the antibody can be used to detect and quantify pi071 protein in solution. The antibody's unconjugated format provides flexibility for researchers to use secondary detection methods of their choice. The product comes with positive control antigens (200μg) and negative control pre-immune serum (1ml), which should be incorporated into experimental designs to validate specificity and minimize false positives .

What are the optimal storage conditions for maintaining pi071 Antibody activity?

Pi071 Antibody should be stored at either -20°C or -80°C to maintain long-term stability and activity. For routine laboratory use, aliquoting the antibody into smaller volumes is recommended to avoid repeated freeze-thaw cycles, which can degrade antibody quality and reduce binding efficiency. When working with the antibody, it should be kept on ice and returned to frozen storage promptly after use. For short-term storage (1-2 weeks), the antibody can be kept at 4°C, but prolonged storage at this temperature is not recommended. Some researchers report adding preservatives such as sodium azide (0.02%) for short-term storage, but caution should be exercised as sodium azide can inhibit the activity of horseradish peroxidase (HRP) often used in detection systems .

How should I design a Western blot experiment using pi071 Antibody?

When designing a Western blot experiment with pi071 Antibody, begin by optimizing protein extraction from yeast samples using a lysis buffer containing protease inhibitors to prevent degradation of your target protein. For S. pombe samples, mechanical disruption (glass bead lysis) often provides better results than chemical lysis methods. The recommended protein loading amount is 20-50μg per lane, with separation on a 10-12% SDS-PAGE gel depending on the molecular weight of pi071.

After transfer to a PVDF or nitrocellulose membrane, block with 5% non-fat dry milk or BSA in TBST for 1 hour at room temperature. Dilute pi071 Antibody at 1:500 to 1:2000 (optimization required) in blocking buffer and incubate overnight at 4°C. Include the provided positive control antigen in a separate lane to confirm antibody functionality. After washing with TBST (3 × 10 minutes), incubate with an anti-rabbit HRP-conjugated secondary antibody at 1:5000 dilution for 1 hour at room temperature. Following additional washes, develop using ECL substrate and image according to your laboratory's standard protocols .

What controls are essential when using pi071 Antibody in research?

A robust experimental design with pi071 Antibody requires multiple controls to ensure valid and reproducible results:

• Positive Control: Use the provided antigen (200μg) to confirm antibody functionality in each experimental run.

• Negative Control: Include the pre-immune serum (provided with the antibody) to establish background binding levels.

• Loading Control: Incorporate antibodies against constitutively expressed proteins (e.g., actin, GAPDH) to normalize for loading variations.

• Knockout/Knockdown Control: When available, include samples from strains with the target gene deleted or silenced to verify antibody specificity.

• Secondary Antibody Control: Include a sample without primary antibody to assess non-specific binding of the secondary antibody.

Additionally, if working with tagged versions of the protein, consider using antibodies against the tag as a complementary approach to validate results. Implement biological replicates (minimum n=3) and technical replicates to ensure statistical robustness and account for experimental variability .

How can I determine the optimal antibody concentration for my specific application?

Determining the optimal concentration of pi071 Antibody requires systematic titration for each specific application and sample type. For Western blotting, prepare a dilution series (e.g., 1:250, 1:500, 1:1000, 1:2000, 1:5000) using identical sample aliquots. Evaluate signal-to-noise ratio, specificity, and background for each dilution. The optimal concentration provides strong specific signal with minimal background.

For ELISA applications, perform a checkerboard titration with varying concentrations of both coating antigen and antibody. Starting with antibody dilutions from 1:100 to 1:10,000 and antigen concentrations from 0.1-10 μg/ml, identify the combination that yields the highest specific signal while maintaining low background readings in negative controls.

Document optimization results in a table format:

Once established, these optimized parameters should be recorded in your laboratory protocols to ensure consistency across experiments .

How can I use pi071 Antibody for studying protein-protein interactions in yeast?

Pi071 Antibody can be employed for investigating protein-protein interactions through co-immunoprecipitation (Co-IP) experiments. For this advanced application, crosslink the antibody to protein A/G beads using a commercial crosslinking kit to prevent antibody contamination in the eluted samples. When preparing yeast lysates, use gentle non-denaturing lysis buffers (e.g., 50 mM Tris-HCl pH 7.5, 150 mM NaCl, 0.5% NP-40, 1 mM EDTA with protease inhibitors) to preserve native protein complexes.

Incubate 1-5 mg of total protein with antibody-conjugated beads overnight at 4°C with gentle rotation. After washing (typically 5 times with decreasing salt concentrations), elute protein complexes using either low pH glycine buffer or by boiling in SDS sample buffer if the crosslinking step was performed. Analyze the immunoprecipitated complexes by Western blotting or mass spectrometry to identify interacting partners.

For validation, perform reciprocal Co-IPs using antibodies against suspected interaction partners, and implement controls including IgG-only immunoprecipitations and, when available, samples from strains lacking the target protein. This approach can reveal novel functional relationships between pi071 and other cellular components in the yeast proteome .

What strategies can address cross-reactivity issues with pi071 Antibody?

When encountering potential cross-reactivity with pi071 Antibody, implement a systematic troubleshooting approach. First, sequence alignment analysis can identify proteins with epitope similarity to pi071 in your experimental system. Pre-adsorption techniques can then be employed by incubating the antibody with excess recombinant cross-reactive proteins prior to use, effectively depleting antibodies that bind to unintended targets.

For Western blotting applications, increasing the stringency of washing conditions (higher salt concentration, addition of 0.1% SDS to wash buffers) can reduce non-specific binding. Alternatively, consider a two-step immunoprecipitation procedure: first, clear the lysate with protein A/G beads alone to remove proteins with affinity for the beads; second, perform the actual immunoprecipitation with fresh beads conjugated to pi071 Antibody.

If cross-reactivity persists, peptide competition assays can be performed by pre-incubating the antibody with specific peptides from the pi071 sequence. This approach not only identifies the specific epitopes recognized by the antibody but also confirms specificity when the peptide successfully blocks antibody binding to the target protein. For critical experiments, validation using orthogonal methods such as CRISPR-engineered knockout strains is highly recommended .

How can I use pi071 Antibody for quantitative analyses of protein expression?

For quantitative analysis of pi071 protein expression, careful standardization and calibration are essential. Begin by establishing a standard curve using purified recombinant pi071 protein at known concentrations (e.g., 0.1, 0.5, 1, 2, 5, 10 ng). For Western blotting applications, implement fluorescent secondary antibodies rather than chemiluminescent detection, as this provides a broader linear dynamic range and more accurate quantification.

When performing quantitative Western blots, include technical replicates (minimum n=3) and internal controls on each blot. Analyze images using specialized software (ImageJ, Li-COR Image Studio) that can perform background subtraction and normalization to loading controls. Report results as relative expression levels normalized to both loading controls and reference samples.

For ELISA-based quantification, develop a sandwich ELISA using pi071 Antibody as either the capture or detection antibody. This approach involves:

• Coating plates with capture antibody (either pi071 Antibody or an antibody against a different epitope of the same protein)

• Blocking with BSA or specialized blocking buffers

• Adding samples and standards in triplicate

• Detecting with either pi071 Antibody or a complementary antibody

• Developing with appropriate substrate

• Measuring absorbance and calculating concentrations using the standard curve

For accurate quantification, all samples should fall within the linear range of the standard curve, typically requiring multiple dilutions of experimental samples .

How should I interpret contradictory results between pi071 Antibody detection and mRNA expression data?

Discrepancies between protein levels detected with pi071 Antibody and corresponding mRNA expression are common and biologically significant. When facing such contradictions, consider multiple factors that can explain these differences:

• Post-transcriptional regulation: mRNA stability, microRNA targeting, and RNA-binding proteins can affect translation efficiency independent of transcript levels.

• Post-translational modifications: Phosphorylation, ubiquitination, or other modifications may alter epitope accessibility or protein stability.

• Protein half-life: The target protein may have a different turnover rate than its mRNA.

• Subcellular localization: Compartmentalization may affect protein extraction efficiency.

• Technical limitations: Incomplete protein extraction or antibody accessibility issues.

When encountering such discrepancies, implement a systematic investigation:

• Verify results using alternative methods (e.g., mass spectrometry for protein, RT-qPCR for mRNA)

• Examine protein stability through cycloheximide chase experiments

• Investigate post-translational modifications using phospho-specific antibodies or mass spectrometry

• Assess protein localization through fractionation or immunofluorescence

Document all findings in a comprehensive table comparing protein and mRNA levels across different experimental conditions, along with possible regulatory mechanisms. This approach transforms apparent contradictions into opportunities for discovering novel regulatory mechanisms affecting the pi071 protein .

What are common false positive/negative scenarios with pi071 Antibody and how can they be addressed?

False results with pi071 Antibody can arise from various sources that require specific mitigation strategies:

False Positives:

• Cross-reactivity: The polyclonal nature of pi071 Antibody means it may recognize epitopes on proteins with structural similarity to the target. Validate with knockout controls and peptide competition assays.

• Non-specific binding: High antibody concentrations can increase background. Optimize antibody dilution and include appropriate blocking steps.

• Secondary antibody issues: Direct binding of secondary antibody to the sample. Include a no-primary-antibody control.

• Sample contamination: Particularly in co-immunoprecipitation experiments. Implement stringent washing protocols and crosslink antibodies to beads.

False Negatives:

• Epitope masking: Post-translational modifications or protein-protein interactions may block antibody access. Try multiple lysis conditions and denaturing protocols.

• Insufficient protein amount: Increase sample loading or concentrate samples.

• Protein degradation: Ensure sufficient protease inhibitors in all buffers and maintain cold chain throughout sample processing.

• Technical issues: Inefficient transfer in Western blots or suboptimal detection methods. Verify with Ponceau S staining and optimize detection settings.

A decision tree approach to troubleshooting can systematically address these issues, beginning with the most common causes and progressing to more complex explanations. For critical experiments, orthogonal validation using methods like mass spectrometry provides definitive confirmation of results .

How can I normalize pi071 Antibody signals for accurate comparison across different experimental conditions?

Accurate normalization is essential for comparing pi071 protein levels across different experimental conditions. Implement a multi-layered normalization strategy:

• Total protein normalization: Use technologies like Stain-Free gels or REVERT total protein stains rather than single housekeeping proteins, which may vary across conditions.

• Internal controls: Include identical reference samples on all blots/plates to account for inter-assay variability.

• Loading controls: When housekeeping proteins must be used, select controls appropriate for your experimental system (e.g., actin for cytoskeletal studies, GAPDH for metabolic investigations).

• Multiple housekeeping proteins: When possible, use a panel of 2-3 housekeeping proteins and calculate a normalization factor based on their geometric mean.

For longitudinal studies, maintain a consistent normalization strategy throughout the project. When experimental conditions might affect all potential protein loading controls (e.g., global translation inhibition), consider spiking samples with a known amount of recombinant protein from a different species as an external reference standard.

Normalized data should be represented as:

Normalized Signal = (Raw Signal of Target) / (Normalization Factor)

Where the normalization factor could be total protein signal, geometric mean of multiple housekeeping proteins, or signal from spiked standard. Report all normalization methodologies transparently in publications to enable reproducibility .

What is the optimal protein extraction protocol for detecting pi071 in yeast samples?

For optimal extraction of pi071 protein from yeast samples, a comprehensive protocol combining mechanical disruption with appropriate buffer composition is recommended:

• Cell Harvesting: Collect 10-20 ml of yeast culture (OD600 = 0.8-1.0) by centrifugation at 3000g for 5 minutes at 4°C. Wash cell pellet twice with ice-cold PBS.

• Cell Lysis Buffer Preparation:

  • 50 mM HEPES pH 7.5

  • 150 mM NaCl

  • 1 mM EDTA

  • 1% Triton X-100

  • 0.1% Sodium deoxycholate

  • 1 mM PMSF (add fresh)

  • Protease inhibitor cocktail (add fresh)

  • Phosphatase inhibitors (if phosphorylation studies are planned)

• Mechanical Disruption: Resuspend cell pellet in 500 μl lysis buffer and add acid-washed glass beads (0.5 mm diameter) to 1/3 of the total volume. Vortex vigorously in 30-second pulses with 30-second cooling on ice between pulses, for a total of 6-8 cycles.

• Lysate Clearing: Centrifuge at 14,000g for 15 minutes at 4°C. Transfer the supernatant to a fresh tube and centrifuge again at 14,000g for 10 minutes to remove any remaining debris.

• Protein Quantification: Determine protein concentration using Bradford or BCA assay, adjusting samples to fall within the linear range of the assay.

This extraction method maintains protein integrity while effectively disrupting yeast cell walls. For membrane-associated proteins, consider adding 0.1% SDS to the lysis buffer, though this may affect antibody recognition in native applications such as immunoprecipitation .

How should I design immunofluorescence experiments using pi071 Antibody?

While pi071 Antibody has not been specifically validated for immunofluorescence, the following protocol can be adapted for this application with appropriate optimization:

• Cell Fixation: Fix yeast cells with 3.7% formaldehyde for 1 hour at room temperature, followed by cell wall digestion with zymolyase (1 mg/ml in sorbitol buffer) for 30 minutes at 30°C.

• Permeabilization: Permeabilize spheroplasts with 0.5% Triton X-100 in PBS for 5 minutes at room temperature.

• Blocking: Block with 3% BSA, 0.1% Tween-20 in PBS for 1 hour at room temperature.

• Primary Antibody: Dilute pi071 Antibody 1:100 to 1:500 (optimization required) in blocking buffer and incubate overnight at 4°C in a humid chamber.

• Washing: Wash 5 times with PBS containing 0.1% Tween-20, 5 minutes each.

• Secondary Antibody: Incubate with fluorophore-conjugated anti-rabbit secondary antibody (1:1000) for 1 hour at room temperature, protected from light.

• Counterstaining: Stain nuclei with DAPI (1 μg/ml) for 5 minutes.

• Mounting: Mount with anti-fade mounting medium.

Critical controls include:

• Primary antibody omission

• Pre-immune serum substitution for primary antibody

• Peptide competition (pre-incubating antibody with immunizing peptide)

• Knockout/knockdown cell lines when available

A systematic optimization of fixation conditions, antibody dilutions, and incubation times is essential, as immunofluorescence protocols often require different conditions than Western blotting .

What approaches can be used to study post-translational modifications of pi071 protein?

Investigating post-translational modifications (PTMs) of pi071 protein requires specialized approaches extending beyond basic antibody applications:

• Phosphorylation Analysis:

  • Treat samples with phosphatase inhibitors during extraction

  • Run parallel samples with and without lambda phosphatase treatment

  • Use Phos-tag acrylamide gels to separate phosphorylated forms

  • Consider phospho-specific antibodies if common phosphorylation sites are known

• Ubiquitination Studies:

  • Include deubiquitinase inhibitors (e.g., N-ethylmaleimide) in lysis buffers

  • Perform immunoprecipitation with pi071 Antibody followed by ubiquitin Western blotting

  • Consider tandem ubiquitin binding entities (TUBEs) for enriching ubiquitinated proteins

• SUMOylation Analysis:

  • Use SUMO-protease inhibitors (e.g., N-ethylmaleimide) in buffers

  • Perform pi071 immunoprecipitation followed by SUMO Western blotting

  • Consider SUMO-specific proteases to confirm modification

• Mass Spectrometry Approach:

  • Immunoprecipitate pi071 protein

  • Perform in-gel or in-solution trypsin digestion

  • Analyze peptides by LC-MS/MS with PTM-specific search parameters

  • Validate MS findings with targeted approaches (e.g., Western blotting)

For comprehensive PTM mapping, consider combining antibody-based approaches with mass spectrometry. When multiple PTMs are present, their interdependence can be studied using site-directed mutagenesis of the modified residues, followed by analysis with pi071 Antibody to observe changes in modification patterns or protein function .