SLC25A13 Antibody

What is SLC25A13 and why is it important in cellular metabolism?

SLC25A13, also known as citrin, functions as a mitochondrial aspartate/glutamate carrier isoform 2 (AGC2) that exports aspartate from the mitochondrial matrix in exchange for cytosolic glutamate and H+. This protein plays crucial roles in the urea cycle and malate-aspartate shuttle, which are essential for nitrogen metabolism and maintenance of the NADH/NAD+ ratio . The importance of SLC25A13 is highlighted by the fact that its deficiency cannot be compensated by aralar (encoded by SLC25A12), another aspartate/glutamate carrier, due to different expression profiles, particularly in the liver . Understanding SLC25A13 function helps researchers investigate metabolic disorders and mitochondrial transport mechanisms.

What are the optimal applications for SLC25A13 antibodies in research?

SLC25A13 antibodies are versatile reagents suitable for multiple experimental applications. Based on validation data, these antibodies perform optimally in Western Blot (WB) at dilutions of 1:1000-1:8000, Immunohistochemistry (IHC) at 1:50-1:500, Immunofluorescence (IF/ICC) at 1:50-1:500, and Immunoprecipitation (IP) using 0.5-4.0 μg for 1.0-3.0 mg of total protein lysate . When designing experiments, researchers should note that while the calculated molecular weight of SLC25A13 is 74 kDa, it typically appears at 60-63 kDa in Western blots . For optimal results, each antibody should be titrated in your specific experimental system, as performance may vary depending on sample type and preparation methods.

What cell lines and tissues show reliable SLC25A13 expression for antibody validation?

For reliable antibody validation, several cell lines and tissues have demonstrated consistent SLC25A13 expression. Western blot analysis has successfully detected SLC25A13 in HEK-293T cells, A431 cells, HEK-293 cells, Raji cells, as well as mouse kidney tissue, liver tissue, and ovary tissue . For immunohistochemistry, human colon cancer tissue has yielded positive results. Immunofluorescence studies have successfully detected SLC25A13 in U2OS cells . When validating a new SLC25A13 antibody batch, these validated positive controls serve as essential benchmarks for confirming antibody specificity and sensitivity.

How should antigen retrieval be optimized for SLC25A13 immunohistochemistry?

Optimal antigen retrieval is critical for successful SLC25A13 detection in fixed tissues. For SLC25A13 immunohistochemistry, the primary recommendation is to use TE buffer at pH 9.0 for antigen retrieval . If this approach yields suboptimal results, an alternative retrieval method using citrate buffer at pH 6.0 can be attempted . The efficacy of antigen retrieval may vary based on tissue type, fixation duration, and embedding conditions. When establishing a new IHC protocol, researchers should conduct a comparison between both retrieval methods using serial sections from the same tissue block to determine which condition provides optimal staining with minimal background. Control tissues with known SLC25A13 expression, such as human colon cancer tissue, should be processed in parallel to validate positive staining.

What considerations should be made when using SLC25A13 antibodies for detecting citrin deficiency in research samples?

When designing experiments to detect citrin deficiency using SLC25A13 antibodies, several methodological considerations are essential. Western blotting provides a reliable approach for analyzing citrin protein expression in patient samples. Extracting mitochondrial protein from peripheral blood lymphocytes (PBLs) has proven effective for this purpose, as demonstrated in NICCD patient studies where citrin signals were absent compared to healthy controls . For optimal results, include both positive and negative controls in each experiment, utilize mitochondrial markers to normalize protein loading, and ensure samples are carefully processed to preserve protein integrity. In cases of suspected citrin deficiency with inconclusive molecular genetic testing, western blotting of citrin protein using patient skin fibroblasts or lymphocytes may provide definitive diagnostic information .

What is the recommended sample preparation protocol for SLC25A13 western blotting?

Effective sample preparation is crucial for successful SLC25A13 detection by western blotting. Begin by extracting total protein or preparing mitochondrial fractions from tissues or cell lines with known SLC25A13 expression (HEK-293T cells, mouse liver or kidney tissue) . For consistent results, homogenize samples in a buffer containing protease inhibitors and maintain cold temperatures throughout processing to prevent protein degradation. Since the observed molecular weight of SLC25A13 (60-63 kDa) differs from its calculated molecular weight (74 kDa) , proper denaturation and reduction of samples is essential. Use 20-50 μg of total protein per lane, and separate on 8-10% SDS-PAGE gels for optimal resolution. For transfer, PVDF membranes are recommended, with blocking in 5% non-fat milk or BSA in TBST. Incubate with SLC25A13 antibody at 1:1000-1:8000 dilution , followed by appropriate secondary antibody detection. Include a loading control antibody (such as GAPDH or a mitochondrial marker) for normalization purposes .

How can SLC25A13 antibodies be utilized for identifying novel SLC25A13 mutations in patient samples?

SLC25A13 antibodies serve as valuable tools in the comprehensive molecular diagnosis of citrin deficiency and identification of novel mutations. A sophisticated approach involves combining western blotting with molecular techniques. First, use western blotting with mitochondrial proteins extracted from patient PBLs to determine if citrin protein is absent or abnormal . If protein abnormalities are detected, perform RT-PCR and cDNA cloning of SLC25A13 from patient RNA to identify aberrant mRNA molecules that may indicate underlying mutations . When cDNA analysis reveals discrepancies, conduct semi-quantitative PCR on genomic DNA targeting multiple SLC25A13 exons to detect potential large deletions or insertions, using a reference exon as an internal control . To precisely position mutations, perform family SNP analysis followed by long-range PCR (LA-PCR) to amplify and sequence regions containing potential mutations . This comprehensive methodology has successfully identified novel large SLC25A13 deletions that were undetectable through conventional sequencing approaches.

What strategies can be employed for multiplexing SLC25A13 antibodies with other mitochondrial markers?

For advanced research requiring co-localization or co-expression analysis, multiple strategies can optimize multiplexing of SLC25A13 antibodies with other mitochondrial markers. When designing multiplexed immunofluorescence experiments, select antibodies raised in different host species (rabbit anti-SLC25A13 combined with mouse anti-mitochondrial markers) to avoid cross-reactivity. For western blot multiplexing, consider the molecular weights of target proteins to prevent overlapping signals—SLC25A13 appears at 60-63 kDa , so choose complementary markers with significantly different molecular weights. Sequential detection protocols using stripping and reprobing can be effective when antibody host species cannot be varied. When conducting co-immunoprecipitation experiments to investigate SLC25A13 interactions, use 0.5-4.0 μg of SLC25A13 antibody for 1.0-3.0 mg of total protein lysate , followed by mass spectrometry for interacting protein identification. Always validate multiplexed assays using single-stained controls to ensure specificity and lack of signal bleed-through.

What techniques are available for quantifying SLC25A13 expression levels in clinical samples?

Accurate quantification of SLC25A13 expression is essential for comparing normal and pathological conditions. For protein-level quantification, densitometric analysis of western blots using SLC25A13 antibodies provides semi-quantitative data when normalized to appropriate loading controls . More precise quantification can be achieved using ELISA with SLC25A13 antibodies, though this requires careful standardization with recombinant SLC25A13 protein. For transcript-level analysis, RT-qPCR targeting SLC25A13 mRNA offers sensitive quantification, particularly useful when protein is undetectable. An advanced approach combines western blotting with semi-quantitative PCR analysis to correlate protein levels with genetic alterations . When analyzing clinical samples, perform parallel analysis of PSTI (pancreatic secretory trypsin inhibitor) levels, as elevated serum PSTI can help distinguish citrin deficiency from conventional NAFLD when genetic testing is inconclusive . For research requiring absolute quantification, consider proteomics approaches using isotope-labeled standards and mass spectrometry.

How can researchers address discrepancies between calculated and observed molecular weights of SLC25A13?

The discrepancy between the calculated molecular weight of SLC25A13 (74 kDa) and its observed migration on SDS-PAGE (60-63 kDa) is a common source of confusion in western blot analysis. This difference likely results from several factors: post-translational modifications, protein folding characteristics, or potential proteolytic processing during sample preparation. To address this discrepancy, researchers should:

• Verify antibody specificity using positive controls with known SLC25A13 expression (HEK-293T cells, mouse liver tissue)

• Include a knockout or knockdown sample as a negative control

• Test different sample preparation conditions to minimize potential proteolysis

• Consider running gradient gels (4-15%) to improve resolution

• Perform parallel analysis with multiple SLC25A13 antibodies targeting different epitopes

If multiple bands appear, perform subcellular fractionation to confirm mitochondrial localization of the true SLC25A13 signal. For publication-quality data, include positive controls and molecular weight markers in all western blot images to demonstrate the expected migration pattern.

What are the common pitfalls in SLC25A13 antibody-based experiments and how can they be avoided?

Researchers frequently encounter several challenges when working with SLC25A13 antibodies. One common issue is non-specific binding, which can be minimized by optimizing antibody dilutions (1:1000-1:8000 for WB, 1:50-1:500 for IHC/IF) and using more stringent washing protocols. Background signal in immunohistochemistry can be reduced by testing alternative antigen retrieval methods (TE buffer pH 9.0 versus citrate buffer pH 6.0) . For western blotting, inconsistent results may stem from incomplete protein transfer; using PVDF membranes and verifying transfer efficiency with protein staining can address this issue. When working with clinical samples, variable SLC25A13 expression between individuals may complicate interpretation, necessitating appropriate normalization controls. For molecular diagnosis, relying solely on antibody-based detection might miss certain mutations; combining western blotting with genetic analysis provides more definitive results . Lastly, proper storage of antibodies (at -20°C with glycerol and sodium azide) maintains reactivity over time, preventing sensitivity loss from repeated freeze-thaw cycles.

How can researchers validate SLC25A13 antibody specificity in their experimental systems?

Rigorous validation of SLC25A13 antibody specificity is essential for generating reliable research data. A comprehensive validation approach should include multiple complementary methods:

• Positive control tissues/cells: Confirm signal in tissues with known SLC25A13 expression (HEK-293T cells, A431 cells, mouse kidney and liver tissue)

• Negative controls: Test antibody reactivity in:

  • SLC25A13 knockout or knockdown models

  • Samples from patients with confirmed citrin deficiency lacking SLC25A13 protein

  • Primary antibody omission controls

• Peptide competition assay: Pre-incubate antibody with immunogen peptide to block specific binding

• Orthogonal methods: Correlate antibody detection with SLC25A13 mRNA expression by RT-PCR

• Multiple antibodies: Compare staining patterns using antibodies targeting different SLC25A13 epitopes (polyclonal vs. monoclonal)

These validation steps should be documented before proceeding with experimental applications, particularly when studying novel tissue types or experimental conditions not previously validated with the specific antibody.

How can SLC25A13 antibodies contribute to the molecular diagnosis of citrin deficiency disorders?

SLC25A13 antibodies provide valuable complementary diagnostic tools in the molecular evaluation of citrin deficiency disorders. While definitive diagnosis typically requires identification of pathogenic SLC25A13 variants on both alleles, western blotting using SLC25A13 antibodies can resolve cases where genetic testing is inconclusive . This approach is particularly valuable when only a single pathogenic variant is detected in a patient with clinical suspicion of citrin deficiency. For diagnostic applications, researchers should extract mitochondrial proteins from patient-derived fibroblasts or lymphocytes and analyze citrin expression by western blotting . Complete absence of citrin protein strongly supports the diagnosis of citrin deficiency, even when the second mutation remains unidentified by conventional sequencing. This antibody-based approach has proven especially useful in detecting large deletions, insertions, or intronic mutations that might be missed by exon-focused sequencing . For comprehensive evaluation, researchers should integrate antibody-based protein detection with molecular genetic analysis and biochemical markers like elevated serum PSTI levels, which can distinguish citrin deficiency from conventional NAFLD .

What are the key methodological considerations when using SLC25A13 antibodies for analyzing different age-dependent phenotypes of citrin deficiency?

Citrin deficiency manifests as three distinct age-dependent clinical phenotypes: Neonatal Intrahepatic Cholestasis caused by Citrin Deficiency (NICCD) in infants, Failure to Thrive and Dyslipidemia caused by Citrin Deficiency (FTTDCD) in children, and adult-onset citrullinemia type II (CTLN2) in adolescents/adults . When investigating these phenotypes using SLC25A13 antibodies, researchers must consider several methodological factors:

• Sample selection: Different tissue types may be available depending on age group (liver biopsies from NICCD patients, peripheral blood lymphocytes for all age groups)

• Sample processing: Age-dependent differences in protein extraction efficiency require optimization of protocols for each sample type

• Quantification approach: Semi-quantitative western blotting should include age-matched controls for proper comparison, as mitochondrial content may vary with age

• Complementary markers: Include analysis of:

  • Aspartate/glutamate ratios to assess carrier function

  • Citrin-associated proteins to detect compensatory mechanisms

  • PSTI levels, which are elevated in citrin deficiency patients

• Correlative analysis: Integrate antibody-based protein detection with clinical parameters specific to each age-dependent phenotype (cholestasis markers for NICCD, amino acid profiles for CTLN2)

These methodological considerations ensure accurate interpretation of SLC25A13 antibody results across different clinical manifestations of citrin deficiency.

How do researchers correlate SLC25A13 mutation types with protein expression patterns using antibody-based detection?

Correlating SLC25A13 mutation types with protein expression patterns requires sophisticated analysis combining antibody-based detection with molecular genetic data. Research indicates that among the 146 pathogenic/likely pathogenic SLC25A13 variants identified, there are 35 deletion/insertion mutations, 34 nonsense mutations, 31 splice site mutations, 13 missense mutations, and 1 silent mutation . Each mutation type may result in distinct protein expression patterns:

• Nonsense and frameshift mutations typically result in complete absence of detectable protein due to nonsense-mediated mRNA decay or truncated proteins

• Missense mutations may yield full-length protein with altered function, detectable by western blotting but potentially showing abnormal subcellular localization by immunofluorescence

• Splice site mutations often produce aberrant mRNA species that can be identified through RT-PCR and cDNA cloning prior to protein analysis

• Large deletions require a combination of semi-quantitative PCR, cDNA analysis, and western blotting for comprehensive characterization

To establish genotype-phenotype correlations, researchers should perform western blotting with SLC25A13 antibodies on patient samples with known mutations, quantify protein levels through densitometry, and correlate findings with clinical severity. This approach has successfully identified novel SLC25A13 mutations, including large deletions that were undetectable through conventional sequencing methods .