MID1IP1 (Mid1-interacting protein 1), also known as MIG12 or THRSPL, is a 20–23 kDa protein involved in hepatic lipogenesis and microtubule dynamics . The FITC-conjugated MID1IP1 antibody enables fluorescent detection of this protein in assays such as immunofluorescence (IF), flow cytometry, and immunohistochemistry (IHC). The FITC conjugate binds to the antibody’s Fc region via covalent linkage, allowing target visualization under fluorescence microscopy or flow cytometry .
Immunohistochemistry (IHC): Validated in paraffin-embedded tissues (e.g., human stomach) .
Flow Cytometry: Used for cell surface or intracellular staining .
Immunofluorescence (IF): Localizes MID1IP1 in cytoplasmic and nuclear compartments .
FITC conjugation involves:
Antibody Dialysis: Purified MID1IP1 antibody is dialyzed against pH 9.5 buffer to remove amines .
Reaction: FITC is added at 25 mg/ml IgG, incubated for 2 hours at room temperature .
Purification: Unbound FITC is removed via gradient DEAE chromatography .
Quality Control: F/P (fluorescein-to-protein) ratio is optimized to balance signal intensity and specificity .
Cancer Research: MID1IP1 overexpression correlates with c-Myc signaling in liver and colon cancers, making it a biomarker for tumor progression .
Lipogenesis: MID1IP1 enhances acetyl-CoA carboxylase (ACACA) activity, driving triglyceride synthesis .
Batch Variability: FITC labeling indices inversely correlate with antigen-binding affinity; over-labeling increases nonspecific staining .
Storage Stability: Maintain at -20°C in glycerol-containing buffers to prevent aggregation .
MID1IP1, also known as Gastrulation-specific G12-like protein, Mid1-interacting G12-like protein, or Spot 14-related protein (S14R), is a 183 amino acid protein belonging to the SPOT14 family . This protein plays several important biological roles:
Involvement in the biosynthesis of triglycerides with medium-length fatty acid chains
Modulation of lipogenesis by interacting with acetyl-CoA carboxylase (ACACA)
MID1IP1 has a molecular weight of approximately 20 kDa, though it may be observed at 23 kDa and 46 kDa in some experimental conditions, with the latter potentially representing dimerized forms . The protein can localize to both the nucleus and cytoplasm, and may form homodimers in the absence of THRSP (Thyroid hormone-responsive protein) .
FITC conjugation involves the chemical attachment of fluorescein isothiocyanate to antibodies, creating a fluorescent-labeled immunoglobulin. This process:
Enables direct visualization of antibody binding through fluorescence microscopy, flow cytometry, and other fluorescence-based techniques
Adds a fluorescent tag with excitation/emission spectra of approximately 495 nm/520 nm, producing green fluorescence
May slightly alter the antibody's binding characteristics compared to unconjugated versions
The conjugation process is highly dependent on reaction conditions, including:
pH (optimal at approximately 9.5)
Temperature (room temperature provides efficient labeling)
Protein concentration (25 mg/ml initial concentration is effective)
Reaction time (maximal labeling typically occurs within 30-60 minutes)
Over-labeling can potentially affect antibody functionality, which is why optimally labeled antibodies are often separated from under- and over-labeled proteins through techniques like gradient DEAE Sephadex chromatography .
Proper storage is critical for maintaining antibody activity and fluorescence intensity:
Some preparations may be refrigerated at 2-8°C for up to 6 months
Avoid repeated freeze-thaw cycles as they can degrade antibody quality and reduce fluorescence
Store in appropriate buffer systems, typically containing preservatives like 0.03% Proclin 300 or 0.09% sodium azide
Some formulations include stabilizers such as 50% glycerol and PBS at pH 7.4
For optimal results, aliquot the antibody upon receipt to minimize freeze-thaw cycles. When handling FITC-conjugated antibodies, protect from light to prevent photobleaching of the fluorophore.
When designing flow cytometry experiments with FITC-conjugated MID1IP1 antibodies, several controls are essential:
Negative Controls:
Isotype control (FITC-conjugated rabbit IgG with no specific target)
Unstained cells (to establish autofluorescence baseline)
Secondary antibody only (if using an indirect staining method)
Positive Controls:
Gating Controls:
Single-color controls for compensation when performing multi-color flow cytometry
FMO (Fluorescence Minus One) controls to establish gating boundaries
As shown in flow cytometric analysis of 293 cells using MID1IP1 antibody, there is a clear shift in fluorescence intensity between negative controls (left histogram) and MID1IP1-positive samples (right histogram) . This demonstrates the specificity of the antibody and establishes a reliable gating strategy.
Optimal dilution factors vary by application technique:
These dilutions serve as starting points, and researchers should conduct titration experiments to determine optimal concentrations for their specific experimental conditions. The antibody's performance can vary based on sample type, fixation method, and detection system used .
Effective sample preparation is crucial for accurate MID1IP1 detection:
For Flow Cytometry:
Single-cell suspensions should be fixed with 2-4% paraformaldehyde
Permeabilization may be necessary for intracellular staining
Cell concentration should be adjusted to 1×10^6 cells/mL for optimal results
For Immunohistochemistry:
Formalin-fixed, paraffin-embedded tissues require antigen retrieval
Human stomach tissue shows reliable staining results with appropriate peroxidase conjugation of secondary antibodies and DAB staining
Sections should be deparaffinized, rehydrated, and subjected to heat-induced epitope retrieval (HIER)
For Western Blotting:
Cell lysates from HEK-293 cells show clear detection of MID1IP1
Both transfected and non-transfected cells can be used to demonstrate specificity
Protein concentration should be carefully quantified for consistent loading
When investigating MID1IP1 expression across different tissues, researchers should note its variable expression pattern, with notable presence in tissues that synthesize triglycerides .
Several factors can lead to non-specific binding and false-positive results:
Suboptimal antibody purification:
Improper blocking:
Insufficient blocking can lead to high background
Optimize blocking buffer composition (typically 1-5% BSA or serum)
Extend blocking time if background persists
Cross-reactivity issues:
FITC conjugation ratio:
FITC is susceptible to photobleaching, which can compromise experimental results. To minimize this effect:
Sample preparation considerations:
Use anti-fade mounting media containing agents like DABCO or ProLong Gold
Keep samples in the dark when not actively imaging
Prepare samples immediately before imaging when possible
Microscopy settings optimization:
Reduce excitation light intensity to the minimum needed for adequate signal
Minimize exposure time during image acquisition
Use neutral density filters to attenuate excitation light
Employ confocal microscopy with pinhole settings that maximize signal-to-noise ratio
Acquisition strategies:
Capture FITC images first in multi-channel experiments
Use frame averaging rather than increasing excitation intensity
Implement deconvolution algorithms to enhance signal from lower-intensity images
Consider time-lapse intervals carefully to reduce cumulative exposure
By implementing these strategies, researchers can obtain reliable fluorescence data while preserving signal intensity throughout their imaging sessions.
MID1IP1 has a calculated molecular weight of approximately 20 kDa, but researchers frequently observe bands at different molecular weights:
Common observed patterns:
Factors affecting observed molecular weight:
Experimental validation approaches:
Compare transfected versus non-transfected cell lysates to confirm specificity
Use reducing vs. non-reducing conditions to evaluate dimer formation
Perform knockout/knockdown studies to verify band identity
Consider analyzing both nuclear and cytoplasmic fractions as MID1IP1 localizes to both compartments
When comparing experimental results with literature, researchers should note both the predicted molecular weight (20 kDa) and commonly observed variations (23 kDa, 46 kDa) to properly interpret their Western blot data .
Co-localization studies provide valuable insights into protein-protein interactions and spatial relationships within cells:
Experimental design for co-localization:
Combine FITC-conjugated MID1IP1 antibody with antibodies against potential interaction partners (e.g., THRSP, ACACA) labeled with spectrally distinct fluorophores
Use double immunofluorescence staining with primary antibodies from different host species
Select fluorophores with minimal spectral overlap (e.g., FITC + Cy3 or FITC + Alexa 647)
Technical considerations:
Optimize fixation methods to preserve protein-protein interactions
Consider proximity ligation assays (PLA) for quantitative assessment of close interactions
Implement super-resolution microscopy techniques for detailed co-localization analysis
Relevant interaction partners:
Co-localization studies would be particularly valuable in investigating MID1IP1's role in lipogenesis and transcriptional regulation, providing insights into its mechanistic actions within different cellular compartments.
Investigating MID1IP1 expression in disease contexts requires multiple complementary approaches:
Cancer research applications:
Metabolic disease models:
Experimental methodologies:
RNA interference or CRISPR-based approaches to modulate MID1IP1 expression
Flow cytometry with FITC-conjugated MID1IP1 antibody to quantify expression levels at single-cell resolution
Tissue microarrays to assess expression across multiple patient samples simultaneously
Recent publications highlight the relevance of MID1IP1 in colorectal cancer, where inhibition of CNOT2 induces apoptosis via MID1IP1, and acetylcorynoline induces apoptosis and G2/M phase arrest through the c-Myc signaling pathway .
Combining antibody-based studies with functional genomics creates powerful research workflows:
Integration with CRISPR screening:
Use genome-wide or targeted CRISPR screens to identify genes that modulate MID1IP1 expression or function
Follow with antibody-based validation using FITC-conjugated MID1IP1 antibody
Quantify effects through flow cytometry or high-content imaging
Multi-omics approaches:
Correlate protein-level measurements (via antibody-based techniques) with:
Transcriptomic data (RNA-seq)
Epigenomic profiles (ChIP-seq)
Metabolomic measurements (especially lipid profiles)
This integration provides insights into regulatory mechanisms
Pathway analysis frameworks:
Clinical correlations:
Through these integrated approaches, researchers can develop comprehensive models of MID1IP1 function in normal physiology and disease states, potentially revealing new therapeutic targets or diagnostic markers.
Several cutting-edge technologies show promise for advancing MID1IP1 research:
Advanced imaging approaches:
Super-resolution microscopy to visualize subcellular localization with nanometer precision
Live-cell imaging with photoactivatable fluorescent proteins to track dynamic behaviors
Correlative light and electron microscopy (CLEM) to connect fluorescence data with ultrastructural context
Single-cell analysis technologies:
Single-cell Western blotting to measure MID1IP1 levels in individual cells
Mass cytometry (CyTOF) combining MID1IP1 antibodies with metal tags for high-parameter analysis
Single-cell RNA-seq paired with protein detection for integrated expression analysis
Proximity-based interactome mapping:
BioID or APEX2 proximity labeling fused to MID1IP1 to identify interaction partners
FRET-based assays using FITC-conjugated antibodies to detect protein-protein interactions
Mass spectrometry-based approaches to comprehensively map the MID1IP1 interactome
These technologies can provide unprecedented insights into MID1IP1 function, regulation, and potential roles in disease processes.
Given MID1IP1's roles in lipogenesis and metabolic regulation, research in this area could have significant therapeutic implications:
Potential therapeutic applications:
Targeting MID1IP1-ACACA interactions to modulate lipid synthesis in metabolic disorders
Exploring connections between MID1IP1 and THRSP in lipid metabolism regulation
Investigating MID1IP1's role in cancer metabolism, particularly in lipid-dependent tumors
Model systems for therapeutic development:
Cell-based assays using FITC-conjugated MID1IP1 antibodies to screen compound libraries
Animal models with altered MID1IP1 expression to evaluate metabolic phenotypes
Patient-derived organoids to assess clinical relevance of MID1IP1 modulation
Biomarker potential:
Evaluating MID1IP1 expression levels as indicators of metabolic disease progression
Monitoring changes in response to therapeutic interventions
Correlating with clinical outcomes in conditions like fatty liver disease or cancer
Future research integrating MID1IP1 antibody-based studies with metabolic profiling could reveal novel intervention points for disorders characterized by dysregulated lipid metabolism.