GT11 Antibody

What is GT11 Antibody and what specific target does it recognize?

GT11 Antibody is a rabbit-derived antibody developed against a specific 12-amino acid peptide sequence near the C-terminus of mouse/rat brain glucose transporter-1 (Glut-1). The antibody is generated by coupling this peptide sequence (with an added cysteine at the NH2 terminus) to KLH (keyhole limpet hemocyanin) as a carrier protein. The resulting antibody specifically recognizes Glut-1, which typically appears as a band of approximately 42-45 kDa in Western blot applications. This antibody has been validated for detection of Glut-1 from multiple species including rat, mouse, human, and rabbit, making it versatile for comparative studies across mammalian models .

What are the available forms of GT11 Antibody and how should each be used?

GT11 Antibody is available in several different preparations, each optimized for specific experimental applications:

• GT11-S: Neat serum form (100 μl solution or lyophilized)

• GT11-A: Affinity-purified antibody (100 μg, supplied at 1 mg/ml in PBS with 0.1% BSA as stabilizer)

• GT11-P: Control peptide used for antibody generation (100 μg/100 μl in PBS, pH 7.4)

• GT11-C: Rat Glut-1 positive control for Western blot (100 μl in SDS-PAGE sample buffer)

The neat serum (GT11-S) is typically used at dilutions of 1:1,000 to 1:5,000 for Western blotting when using chemiluminescence detection. The affinity-purified antibody (GT11-A) provides higher specificity and is recommended at concentrations of 1-10 μg/ml for Western blotting and 2-10 μg/ml for immunohistochemistry on frozen tissue sections. The control peptide (GT11-P) can be used to coat ELISA plates at 1 μg/ml, while the positive control (GT11-C) serves as a reference standard for Western blot experiments .

What are the recommended storage conditions for preserving GT11 Antibody activity?

Proper storage is critical for maintaining antibody functionality. For GT11 Antibody:

• Lyophilized products should be reconstituted in 100 μl water and gently mixed for 15 minutes at room temperature before use.

• All antibody solutions (whether received in solution or reconstituted from lyophilized material) should be stored frozen at -20°C or below in appropriate aliquots to minimize freeze-thaw cycles.

• Diluted working solutions are not recommended for long-term storage.

• The antibody preparations contain 0.02% sodium merthiolate as a preservative.

• For the GT11-C positive control, it should be stored frozen in small aliquots and thawed to room temperature before use without additional heating, as excessive heating or repeated freeze-thaw cycles can cause protein aggregation and generation of non-specific high molecular weight bands .

How can GT11 Antibody be optimized for immunoprecipitation experiments?

For immunoprecipitation experiments, GT11 Antibody can be employed using either the neat serum or affinity-purified preparation. The recommended protocol involves:

• Using 5-10 μl of neat serum per 100 μg of rat brain membrane preparation, or alternatively, 1-10 μg of affinity-purified antibody.

• Pre-clearing the sample with protein A/G beads to reduce non-specific binding.

• Incubating the antibody with the sample overnight at 4°C with gentle rotation.

• Adding protein A/G beads and continuing incubation for 2-4 hours.

• Washing the immunoprecipitate thoroughly with PBS or appropriate buffer.

• Eluting the bound proteins using SDS-PAGE sample buffer for subsequent analysis.

This approach has been successfully employed to isolate Glut-1 from various tissue sources, enabling studies of protein-protein interactions and post-translational modifications .

What approaches can be used to validate GT11 Antibody specificity in experimental systems?

Rigorous validation of antibody specificity is essential for meaningful research outcomes. For GT11 Antibody, several complementary approaches can be employed:

• Peptide competition assay: Pre-incubating GT11 Antibody with its cognate peptide (GT11-P) should abolish or significantly reduce specific signals in Western blot, immunohistochemistry, or ELISA applications.

• Positive control validation: The GT11-C positive control can be used to confirm appropriate band detection at 42-45 kDa in Western blot applications.

• Cross-species reactivity verification: The antibody has been documented to detect Glut-1 from human red blood cells, rabbit brain, mouse 3T3 L1 fibroblasts, rat brain and adipocytes, Hep G2 cells, and Caco-2 cells, providing multiple validation options.

• Comparison with other Glut-1 antibodies: Results can be compared with other validated Glut-1 antibodies targeting different epitopes to confirm consistent detection patterns .

How does GT11 Antibody perform in detecting membrane-associated versus cytosolic Glut-1?

Glucose transporters like Glut-1 are integral membrane proteins that can exist in different cellular compartments depending on physiological conditions and cell type. When using GT11 Antibody to distinguish between membrane-associated and cytosolic Glut-1:

• For membrane fraction isolation: Careful subcellular fractionation is required, separating membrane fractions from cytosolic components using differential centrifugation protocols.

• For immunofluorescence studies: The affinity-purified antibody (GT11-A) at 2-10 μg/ml is recommended for frozen tissue sections to visualize membrane localization patterns.

• For confocal microscopy: Co-staining with membrane markers can help confirm proper Glut-1 localization at the plasma membrane versus intracellular compartments.

• For transport studies: Correlating Glut-1 detection with functional glucose uptake assays can provide insights into the proportion of functional (membrane-inserted) versus non-functional (cytosolic) transporter .

What is the recommended protocol for Western blotting with GT11 Antibody?

A systematic Western blotting protocol using GT11 Antibody should include:

• Sample preparation:

  • For tissue samples: Homogenize in RIPA buffer containing protease inhibitors

  • For cell samples: Lyse in appropriate buffer (RIPA or NP-40)

  • Determine protein concentration using Bradford or BCA assay

• Gel electrophoresis and transfer:

  • Separate 20-50 μg protein on 10-12% SDS-PAGE

  • Transfer to PVDF or nitrocellulose membrane (PVDF recommended for higher sensitivity)

• Antibody incubation:

  • Block membrane with 5% non-fat milk or BSA in TBS-T for 1 hour at room temperature

  • Incubate with GT11-S (1:1,000-1:5,000 dilution) or GT11-A (1-10 μg/ml) overnight at 4°C

  • Wash 3x with TBS-T

  • Incubate with appropriate HRP-conjugated secondary antibody (1:5,000-1:10,000) for 1 hour

  • Wash 4x with TBS-T

• Detection:

  • Develop using enhanced chemiluminescence (ECL) reagents

  • Expected result: Major band at 42-45 kDa representing Glut-1

• Controls:

  • Include GT11-C positive control (25 μl/lane without heating)

  • Consider including a peptide competition control (antibody pre-incubated with GT11-P)

How should samples be prepared for optimal GT11 Antibody binding in immunohistochemistry?

For immunohistochemistry applications with GT11 Antibody:

• Tissue processing:

  • Fresh frozen sections (5-8 μm thick) are recommended over paraffin-embedded samples

  • Fix sections in cold acetone or 4% paraformaldehyde for 10 minutes

  • If using paraformaldehyde, permeabilization with 0.1-0.3% Triton X-100 may be necessary

• Blocking and antibody incubation:

  • Block with 5-10% normal serum (species of secondary antibody) for 1 hour

  • Incubate with GT11-A at 2-10 μg/ml overnight at 4°C

  • Wash thoroughly with PBS (3x5 minutes)

  • Apply appropriate labeled secondary antibody

  • Include nuclear counterstain if desired

• Antigen retrieval:

  • May not be necessary for frozen sections

  • For fixed tissues showing reduced signal, consider mild antigen retrieval methods

• Controls:

  • Negative control: Omit primary antibody

  • Blocking control: Pre-incubate antibody with GT11-P control peptide

What approach should be used for quantitative ELISA development using GT11 Antibody?

To develop a quantitative ELISA for Glut-1 detection using GT11 Antibody:

• Direct ELISA format:

  • Coat plates with GT11-P control peptide at 1 μg/ml in carbonate buffer (pH 9.6)

  • Incubate overnight at 4°C

  • Block with 1-3% BSA in PBS-T

  • Add samples and standards containing Glut-1

  • Add GT11-S (1:10,000-1:50,000) or GT11-A (0.5-1 μg/ml)

  • Add appropriate HRP-conjugated secondary antibody

  • Develop with TMB substrate

  • Read absorbance at 450 nm

• Sandwich ELISA format (requires a second Glut-1 antibody targeting a different epitope):

  • Coat plates with capture antibody

  • Add samples containing Glut-1

  • Add GT11-A as detection antibody

  • Add enzyme-conjugated secondary antibody

  • Develop and read as above

• Standard curve preparation:

  • Use purified Glut-1 or synthetic peptide at known concentrations

  • Include both positive and negative controls in each assay

What factors might affect GT11 Antibody detection of Glut-1 in different experimental systems?

Several factors can influence the detection sensitivity and specificity of GT11 Antibody across experimental systems:

• Post-translational modifications:

  • Glut-1 undergoes glycosylation which can affect epitope accessibility

  • Phosphorylation states may alter antibody recognition

  • Reduction/oxidation conditions can affect disulfide bonds and protein conformation

• Sample preparation variables:

  • Heat treatment may cause protein aggregation, particularly for membrane proteins

  • Detergent selection is critical for proper solubilization (avoid harsh detergents)

  • Freeze-thaw cycles can degrade protein integrity and epitope structure

• Species variations:

  • While the targeted peptide sequence has high homology across species (100% identical in mouse, rat, human, rabbit, bovine, and pig; 90% homology in chicken), subtle differences in post-translational modifications may affect detection

  • Expression levels vary significantly across tissues and species

• Technical considerations:

  • Transfer efficiency in Western blotting affects detection sensitivity

  • Fixation methods in immunohistochemistry can mask epitopes

  • Background reduction techniques may inadvertently reduce specific signal

How can non-specific binding be distinguished from specific Glut-1 signal when using GT11 Antibody?

Differentiating specific from non-specific signals is crucial for accurate data interpretation:

• Peptide competition controls:

  • Pre-incubate GT11 Antibody with increasing concentrations of GT11-P control peptide

  • Specific signals should diminish proportionally with peptide concentration

  • Non-specific signals typically remain unchanged

• Molecular weight verification:

  • Glut-1 should appear at 42-45 kDa

  • Additional bands may represent:

    • Degradation products (lower MW)

    • Glycosylation variants (higher MW)

    • Protein aggregates (much higher MW)

    • Non-specific binding (variable MW)

• Positive control comparison:

  • Compare experimental samples with GT11-C positive control

  • Band patterns should be consistent between samples and positive control

• Secondary antibody-only control:

  • Omit primary antibody (GT11) to identify signals arising from secondary antibody alone

  • These signals represent true non-specific binding

What experimental approaches can address potential cross-reactivity with other glucose transporter isoforms?

Glucose transporters comprise a family of related proteins with structural similarities that may lead to cross-reactivity. To address this:

• Sequence analysis:

  • The GT11 Antibody targets a 12 AA peptide near the C-terminus of Glut-1

  • Compare this sequence with corresponding regions of other glucose transporter isoforms

  • High sequence homology may predict potential cross-reactivity

• Knockout/knockdown validation:

  • Use Glut-1 knockout/knockdown samples as negative controls

  • Persistent signal in these samples suggests cross-reactivity

• Recombinant protein panel testing:

  • Test GT11 Antibody against a panel of recombinant glucose transporter isoforms

  • Detect binding specificity using Western blot or ELISA

• Comparative analysis with isoform-specific antibodies:

  • Run parallel experiments with well-characterized antibodies specific for other glucose transporter isoforms

  • Compare detection patterns to identify potential overlap

How does GT11 Antibody compare with other systems for detecting Glut-1 expression?

When comparing GT11 Antibody with alternative detection methods for Glut-1:

• Alternative antibody approaches:

  • Monoclonal vs. polyclonal: GT11 is a polyclonal antibody offering potentially broader epitope recognition compared to monoclonals which may provide higher specificity for a single epitope

  • Epitope targeting: Antibodies targeting different regions of Glut-1 may yield complementary data

  • Species origin: Rabbit-derived antibodies like GT11 often show high affinity and specificity

• Non-antibody detection methods:

  • Fluorescently-labeled glucose analogs can detect functional transporters but not total protein levels

  • RNA-based methods (qPCR, RNA-Seq) measure transcript levels which may not correlate with protein expression

  • Mass spectrometry provides unbiased detection but requires specialized equipment

• GT11 advantages:

  • Cross-species reactivity (human, rabbit, mouse, rat)

  • Multiple validated applications (Western, IHC, IP, ELISA)

  • Available in multiple formats (serum, affinity-purified)

What are the methodological considerations when using GT11 Antibody to study Glut-1 in cancer research?

Cancer cells frequently upregulate glucose transporters to support increased glycolytic metabolism. When using GT11 Antibody in cancer research:

• Comparative analysis approaches:

  • Compare Glut-1 levels between tumor and adjacent normal tissue

  • Correlate Glut-1 expression with tumor grade, stage, and patient outcomes

  • Examine co-expression with other metabolic markers (HIF-1α, PDK1, etc.)

• Technical considerations:

  • High background in tumor tissues may require optimization of blocking conditions

  • Hypoxic regions may show differential Glut-1 expression requiring spatial analysis

  • Heterogeneous expression necessitates analysis of multiple tumor regions

• Validation strategies:

  • Correlate protein detection with functional glucose uptake (using FDG or other glucose analogs)

  • Combine with mRNA analysis to assess transcriptional vs. post-transcriptional regulation

  • Consider membrane fractionation to distinguish surface-expressed vs. internal Glut-1

• Therapeutic implications:

  • Monitor Glut-1 expression changes in response to treatments

  • Correlate with glycolytic inhibitor sensitivity

  • Assess relationship with drug resistance phenotypes

How can GT11 Antibody be integrated with lambda gt11 expression systems in molecular biology research?

The lambda gt11 expression system represents a powerful molecular biology tool that can be complemented by GT11 Antibody in several ways:

• Expression screening applications:

  • Lambda gt11 expresses open reading frames as beta-galactosidase fusion proteins in infected E. coli

  • Libraries can be screened with GT11 Antibody to identify Glut-1-interacting proteins

  • This approach has been successful in mapping genes for other proteins, as demonstrated with cytomegalovirus proteins

• Epitope mapping:

  • Generate truncated or mutated versions of Glut-1 in lambda gt11

  • Screen with GT11 Antibody to precisely map the recognition epitope

  • Confirm epitope predictions from peptide sequence analysis

• Cross-reactivity analysis:

  • Express various glucose transporter isoforms in lambda gt11

  • Screen with GT11 Antibody to assess potential cross-reactivity

  • Identify shared epitopes across the transporter family

• Protein-protein interaction studies:

  • Express putative Glut-1 interacting proteins in lambda gt11

  • Use co-immunoprecipitation with GT11 Antibody to detect interactions

  • Validate interactions identified through other screening methods