isoc2 Antibody

What is ISOC2 and why is it a target of interest in research?

ISOC2 (Isochorismatase Domain Containing 2) is a mitochondrial protein with isochorismatase domain that plays a role in protein destabilization according to gene ontology annotations . It is expressed in multiple tissues including kidney, liver, and testis, making it relevant for studies involving these organ systems . ISOC2 antibodies are valuable tools for investigating the expression patterns and functions of this protein across different experimental contexts and tissue types. Understanding ISOC2's localization and expression profiles is particularly important for mitochondrial research, as immunofluorescent staining has confirmed its mitochondrial localization in human cell lines such as HEK 293 .

What criteria should be considered when selecting an ISOC2 antibody for research?

When selecting an ISOC2 antibody, researchers should consider several critical parameters: (1) Host species and clonality - most available ISOC2 antibodies are rabbit polyclonal antibodies , which may influence cross-reactivity and batch consistency; (2) Validated applications - confirm the antibody has been validated for your specific application (WB, IHC, ELISA) as performance varies between applications ; (3) Species reactivity - available antibodies show reactivity with human, mouse, and rat samples with varying degrees of cross-reactivity ; (4) Epitope recognition - antibodies targeting different regions of ISOC2 are available, including N-terminal, C-terminal, and middle regions ; and (5) Validation methods - consider antibodies validated through enhanced methods such as siRNA knockdown or GFP-tagged cell lines . Review validation images and supplementary data carefully to ensure the antibody performs consistently in experimental conditions similar to your planned studies.

How do ISOC2 antibodies differ in terms of reactivity across species?

ISOC2 antibodies demonstrate variable cross-reactivity profiles across species, an important consideration for comparative studies. The Proteintech antibody (27082-1-AP) has been validated to react with human, mouse, and rat samples , providing versatility for cross-species research. Abbexa's antibody is primarily validated for human reactivity but is predicted to also react with mouse and rat ISOC2 . The Thermo Fisher Scientific antibody shows highest sequence identity with mouse (86%) and rat (90%) orthologs , suggesting good cross-reactivity potential. When conducting multi-species experiments, preliminary validation in each species is recommended, as sequence homology predictions don't always translate to functional reactivity. For critical experiments comparing ISOC2 across evolutionary lines, western blotting at different antibody concentrations may be necessary to normalize detection sensitivity across species.

What are the optimal conditions for Western blot using ISOC2 antibodies?

Optimal Western blot conditions for ISOC2 antibodies vary by manufacturer but follow these general guidelines based on validated protocols. For dilution, Proteintech's antibody (27082-1-AP) performs optimally at 1:1000-1:6000 , while Abbexa's antibody requires 1:500-1:2000 . When detecting ISOC2, researchers should anticipate observing bands at approximately 22-28 kDa, depending on the antibody used - Proteintech reports 28 kDa while Abbexa reports 22 kDa . This discrepancy may reflect differences in post-translational modifications or isoform detection.

For sample preparation, positive results have been consistently observed in LNCaP cells, mouse kidney, liver, and testis tissues, and rat testis tissue , making these recommended positive controls. Protein loading should be optimized based on expression levels in your specific sample type, with 20-50 μg total protein generally sufficient for detection in tissue lysates. For blocking, 5% non-fat dry milk in TBST is typically effective, though BSA-based blockers may provide cleaner results in some systems. Finally, for optimal visualization, HRP-conjugated secondary antibodies with enhanced chemiluminescence detection systems are recommended due to the moderate expression levels of ISOC2 in most tissues.

What protocol variations are needed for successful immunohistochemistry with ISOC2 antibodies?

Successful immunohistochemistry (IHC) with ISOC2 antibodies requires specific protocol adaptations to achieve optimal staining. For antigen retrieval, Proteintech recommends using TE buffer at pH 9.0, with citrate buffer at pH 6.0 as an alternative option . This suggests that epitope accessibility may be pH-dependent for ISOC2. Regarding dilution factors, recommended ranges are 1:100-1:400 for Proteintech's antibody , 1:100-1:200 for Abbexa's antibody , and 1:100-1:300 for Antibodies-online's product .

For tissue selection, human kidney and liver tissues have been validated as positive controls for ISOC2 staining , making these ideal reference tissues for protocol optimization. When developing staining protocols, progressive dilution series and parallel positive control runs are advisable to determine optimal conditions for specific tissue types. The subcellular localization pattern should appear predominantly mitochondrial based on immunofluorescence data , providing a useful internal validation criterion. Additionally, secondary antibody-only controls are essential to distinguish specific staining from background, particularly important for mitochondrial markers which can show nonspecific staining due to the organelle's abundance and autofluorescence properties.

How should ELISA protocols be optimized when using ISOC2 antibodies?

Optimizing ELISA protocols with ISOC2 antibodies requires careful consideration of antibody concentrations and detection systems. Recommended dilution ranges vary significantly between manufacturers: Proteintech validates their antibody for ELISA without specifying exact dilutions , Abbexa recommends very high dilutions of 1:20000-1:80000 , and Antibodies-online suggests 1:5000-1:10000 . This wide variation indicates that optimal dilution should be empirically determined for each experimental system.

For sandwich ELISA development, considering the availability of antibodies recognizing different epitopes of ISOC2 is advantageous - several manufacturers offer antibodies targeting different regions (AA 1-205, AA 26-203, AA 75-125, AA 159-188) , potentially allowing for capture-detection antibody pairs targeting distinct regions. When developing quantitative ELISA assays, generation of standard curves using recombinant ISOC2 protein is recommended, with careful attention to the specific region used as immunogen in your selected antibody. For enhanced sensitivity in low-expression contexts, amplification systems such as biotin-streptavidin detection may be beneficial, with some manufacturers offering biotin-conjugated versions of their ISOC2 antibodies .

What validation methods ensure specificity of ISOC2 antibody staining?

Ensuring ISOC2 antibody specificity requires implementing multiple validation strategies. Standard validation methods compare antibody staining with available experimental gene/protein characterization data in databases like UniProtKB/Swiss-Prot, resulting in ratings of "Supported," "Approved," or "Uncertain" . For more rigorous confirmation, enhanced validation techniques should be employed: siRNA knockdown validation measures decreased staining intensity upon target protein downregulation; GFP validation assesses signal overlap between antibody staining and GFP-tagged ISOC2; and independent antibody validation compares staining patterns of antibodies targeting different ISOC2 epitopes .

For definitive specificity confirmation, the Human Protein Atlas recommends using at least two independent antibodies directed toward different epitopes on ISOC2 . This approach is particularly valuable given the availability of antibodies targeting distinct regions of the protein (N-terminal, C-terminal, and middle regions) . When interpreting validation results, researchers should carefully evaluate whether antibodies consistently mark the expected subcellular localization (mitochondria for ISOC2) and produce the predicted molecular weight band in Western blots (approximately 22-28 kDa) . For tissues with complex expression patterns, comparison with mRNA expression data can provide additional confidence in staining specificity.

How should researchers interpret discrepancies in ISOC2 antibody validation data?

When facing discrepancies in ISOC2 antibody validation data, a systematic analysis approach is essential. First, categorize discrepancies by type: (1) Molecular weight differences - the reported ISOC2 molecular weight varies between 22 kDa and 28 kDa , potentially reflecting post-translational modifications, splice variants, or technical variations in gel conditions; (2) Localization patterns - while primarily mitochondrial , variations in cytoplasmic or nuclear staining may indicate context-dependent localization or non-specific binding; and (3) Species-specific detection sensitivity - different antibodies show varying cross-reactivity with mouse and rat orthologs despite sequence similarity .

To resolve these discrepancies, implement a multi-method validation strategy combining orthogonal techniques. For example, if Western blot shows multiple bands, complement with mass spectrometry to identify the authentic ISOC2 band. When localization patterns differ between immunostaining methods, validate with subcellular fractionation followed by Western blotting. For antibodies with contradictory validation ratings, prioritize those with enhanced validation documentation like siRNA knockdown or independent antibody correlation . Most importantly, all validation should be performed in the specific experimental context (cell lines, tissues, species) relevant to your research question, as antibody performance can be highly context-dependent.

How can researchers optimize ISOC2 antibody performance in challenging tissue types?

Optimizing ISOC2 antibody performance in challenging tissues requires methodical modification of standard protocols. For tissues with high autofluorescence or background (such as liver or kidney), which coincidentally are tissues where ISOC2 has been validated , implement specific countermeasures: (1) Extended blocking steps using 5-10% normal serum from the secondary antibody host species; (2) Including 0.1-0.3% Triton X-100 in antibody diluents to enhance penetration; and (3) Utilizing Sudan Black B (0.1-0.3%) post-staining to reduce autofluorescence, particularly for mitochondrial markers like ISOC2 .

For formalin-fixed tissues where epitope masking is problematic, explore alternative antigen retrieval methods beyond the recommended TE buffer (pH 9.0) or citrate buffer (pH 6.0) - consider heat-mediated retrieval with EDTA buffer or enzymatic retrieval with proteinase K for resistant samples. In tissues with low ISOC2 expression, signal amplification systems such as tyramide signal amplification can enhance detection sensitivity while maintaining specificity. When working with archival or poorly preserved specimens, progressive antibody titration starting from higher concentrations than typically recommended (e.g., 1:50 rather than 1:100 for IHC) may be necessary to compensate for antigen degradation.

What are the major pitfalls in quantitative analysis of ISOC2 expression?

Quantitative analysis of ISOC2 expression faces several technical challenges that must be addressed to ensure reliable results. First, normalization approaches must account for ISOC2's mitochondrial localization - standard housekeeping proteins like β-actin or GAPDH may not appropriately control for variations in mitochondrial content between samples. Instead, mitochondrial markers such as VDAC or COX IV provide more appropriate references for quantitative comparisons.

Second, antibody linearity assessment is critical - the relationship between ISOC2 abundance and signal intensity should be validated across a range of protein concentrations to ensure quantitative accuracy. This is particularly important given the wide range of recommended dilutions across manufacturers (1:1000-1:6000 for Western blot) . Third, tissue heterogeneity can significantly impact quantification - since ISOC2 shows differential expression across tissues (validated in kidney, liver, and testis) , cell-type compositional differences between samples must be considered when interpreting expression changes.

For image-based quantification of IHC or immunofluorescence, standardized image acquisition parameters and analysis workflows are essential. Background subtraction methods should be consistent, particularly for mitochondrial markers which may show punctate staining patterns against variable cytoplasmic backgrounds. Finally, when comparing ISOC2 expression between experimental conditions, statistical approaches should account for the typically non-normal distribution of protein expression data, with non-parametric tests often more appropriate than parametric analyses.

How should researchers approach co-localization studies involving ISOC2?

Successful co-localization studies with ISOC2 require careful planning due to its mitochondrial localization . When designing multi-labeling experiments, antibody compatibility must be addressed first - primary antibodies should be from different host species (rabbit polyclonal ISOC2 antibodies pair well with mouse monoclonals against other targets) or utilize directly conjugated antibodies to avoid cross-reactivity during secondary detection. For validated mitochondrial markers to confirm ISOC2 localization, consider MitoTracker dyes for live-cell imaging or antibodies against TOMM20, COX IV, or cytochrome c for fixed samples.

Quantitative co-localization analysis should employ both intensity correlation coefficients (Pearson's or Mander's) and object-based approaches, as ISOC2's punctate mitochondrial distribution may not be adequately captured by pixel-based methods alone. Confocal microscopy with appropriate resolution settings is essential - mitochondria typically range from 0.5-1μm in diameter, requiring sampling at Nyquist criteria to avoid resolution artifacts. When investigating potential functional interactions between ISOC2 and other proteins, proximity ligation assays (PLA) provide higher sensitivity than conventional co-localization for detecting genuine molecular interactions at sub-resolution distances.

For dual immunohistochemistry on tissue sections, sequential staining protocols are preferable to simultaneous incubation when using multiple rabbit primaries (as most ISOC2 antibodies are rabbit-derived ). This approach, combined with spectral unmixing during image acquisition, can overcome the limitations of same-species antibodies in co-localization studies.

How does ISOC2 expression pattern vary across different human tissues?

ISOC2 expression demonstrates a tissue-specific distribution pattern that has important implications for experimental design and data interpretation. Immunohistochemistry validation studies have confirmed positive ISOC2 detection in human kidney and liver tissues , establishing these as reliable positive control tissues for antibody validation. Additional validated positive samples include mouse kidney, liver, and testis tissues, as well as rat testis tissue , suggesting conservation of expression patterns across these mammalian species.

In cell culture systems, LNCaP cells (derived from human prostate cancer) have been validated as positive for ISOC2 expression , making them a useful model for in vitro studies. The mitochondrial localization of ISOC2 has been specifically demonstrated in human HEK 293 cells , which aligns with its classification as a mitochondrial protein. When designing tissue-specific studies, researchers should anticipate variable expression levels across different cell types within complex tissues. For example, in kidney, expression patterns may differ between glomerular, tubular, and interstitial compartments. Standardized assessment of expression should employ semi-quantitative scoring systems that account for both staining intensity and the percentage of positive cells, particularly when evaluating ISOC2 expression changes in disease contexts.

What are the recommended positive and negative controls for ISOC2 antibody validation?

Robust ISOC2 antibody validation requires carefully selected positive and negative controls. For positive tissue controls, human kidney and liver tissues have been explicitly validated for IHC applications . In cellular systems, LNCaP cells provide a reliable positive control for Western blot applications . Additional validated positive controls include mouse kidney, liver, and testis tissues, as well as rat testis tissue , offering options for cross-species studies.

For negative controls, technical approaches should include: (1) Primary antibody omission controls to assess secondary antibody specificity; (2) Isotype controls using non-specific IgG from the same host species and at the same concentration as the ISOC2 antibody; and (3) Absorption controls where the primary antibody is pre-incubated with excess recombinant ISOC2 protein before application to samples. For definitive negative biological controls, CRISPR/Cas9 knockout cell lines or siRNA-mediated knockdown samples provide the most rigorous validation. When enhanced validation methods are available, siRNA knockdown validation provides quantitative data on signal reduction following target depletion , offering a graduated assessment of antibody specificity rather than a simple positive/negative determination.

The standard validation approach comparing antibody results with UniProtKB/Swiss-Prot database information can guide preliminary assessments, but should be supplemented with experimental validation in the specific experimental system being studied.