FMN1 (Formin 1) is a cytoskeletal regulatory protein involved in actin polymerization and adherens junction formation . The HRP-conjugated FMN1 antibody facilitates high-sensitivity detection of FMN1 in human, mouse, and rat samples . Its development leverages synthetic peptides or recombinant protein immunogens, ensuring specificity for FMN1 isoforms .
Compatible with chromogenic substrates (e.g., TMB, DAB) for colorimetric detection .
Validated for serum, plasma, and cell culture supernatants in sandwich ELISA formats .
FMN1 regulates actin cable assembly and adherens junction formation, critical for cell migration and tissue morphogenesis . Deficiency in FMN1 disrupts limb and kidney development in mammals, highlighting its role in embryogenesis .
Linked to limb deformity syndromes in murine models via mutations at the ld locus .
Overexpression or dysregulation may contribute to cancer metastasis due to altered cell adhesion .
FMN1 (Formin 1) is a cytoskeletal protein that plays critical roles in actin filament assembly and organization. It is involved in the formation of adherens junctions and the polymerization of linear actin cables . FMN1 has significant developmental functions, particularly in limb development, which is why it's also known as "Limb deformity protein homolog" .
In neuronal contexts, FMN1 has been identified as a key mediator of dendritogenesis and synaptogenesis. Research has demonstrated that overexpression of the Fmn1-Ib isoform increases the number of primary dendrites by approximately 50% in cultured hippocampal neurons and significantly increases the number of glutamatergic synaptic terminals without affecting GABAergic terminals . FMN1 has been shown to localize to the cytoplasm of neurons, particularly concentrating along microtubules, indicating its role in both actin and microtubule cytoskeletal organization .
Additionally, a circular RNA derived from the FMN1 gene (ciRNA-Fmn1) is specifically enriched in nervous tissue and has been implicated in neuropathic pain regulation through interaction with the ubiquitin ligase UBR5 .
FMN1 Antibody, HRP conjugated has been validated for several laboratory applications including:
The HRP (Horseradish Peroxidase) conjugation provides direct enzymatic detection capability, simplifying experimental protocols by eliminating the need for secondary antibody incubation. This conjugation enables direct visualization through chemiluminescent, colorimetric, or fluorescent substrates depending on the detection system used .
To ensure reliable and reproducible results, researchers should implement multiple validation approaches:
Positive and negative controls:
Use tissues or cell lines with known FMN1 expression as positive controls (neuronal tissues are particularly relevant)
Implement FMN1 knockdown models as biological negative controls
siRNA validation approach:
Research has demonstrated that FMN1-specific siRNAs can effectively reduce both FMN1 mRNA and protein levels, providing an excellent validation system. In particular, siRNA2 and siRNA3 have been shown to significantly reduce FMN1 expression without affecting β-actin levels, demonstrating specificity . This approach can be used to:
Transfect cells with FMN1-specific siRNA
Confirm knockdown by qPCR
Validate antibody specificity by Western blot showing reduced signal intensity
Peptide competition assay:
Pre-incubate the antibody with the immunizing peptide
A significant reduction in signal indicates specificity for the target epitope
Cross-validation with multiple detection methods:
Compare results between different antibody-based techniques (WB, IHC, ELISA)
Correlate protein detection with mRNA expression data
For detecting FMN1 (expected MW: ~158 kDa) in Western blot applications, the following optimized protocol is recommended:
Sample preparation:
Use RIPA or NP-40 lysis buffers containing protease inhibitor cocktails
Denature proteins at 95°C for 5 minutes in Laemmli buffer with reducing agent
Gel electrophoresis parameters:
Use 7-8% polyacrylamide gels for optimal resolution of high molecular weight FMN1
Load 20-50 μg of total protein per lane
Include molecular weight markers covering 100-250 kDa range
Transfer conditions:
Transfer to 0.45 μm nitrocellulose or PVDF membranes
For large proteins like FMN1, use wet transfer at 30V overnight at 4°C or 100V for 2 hours in cold transfer buffer with 10-20% methanol
Blocking and antibody incubation:
Block with 5% non-fat dry milk or BSA in TBST for 1-2 hours at room temperature
Dilute FMN1 Antibody, HRP conjugated at 1:500-1:2,000 in blocking buffer
Incubate overnight at 4°C with gentle rocking
Wash 5-6 times with TBST, 5-10 minutes each
Detection system:
Use enhanced chemiluminescent (ECL) substrate optimized for HRP
Begin with 30-second exposure and adjust as needed
For densitometric analysis, ensure images are captured within the linear range
When analyzing FMN1 in neuronal samples, researchers should be aware that the protein may display altered mobility patterns due to post-translational modifications or tissue-specific expression of different isoforms .
When encountering non-specific bands or high background in experiments with FMN1 Antibody, HRP conjugated, implement these evidence-based troubleshooting strategies:
For Western blot applications:
| Issue | Potential Cause | Solution | Scientific Rationale |
|---|---|---|---|
| Multiple bands | Protein degradation | Add fresh protease inhibitors, keep samples cold | Prevents proteolytic cleavage of FMN1 |
| Isoform detection | Verify with isoform-specific controls | Different FMN1 isoforms have distinct molecular weights | |
| High background | Insufficient blocking | Increase blocking time to 2 hours or overnight | Saturates non-specific binding sites |
| Antibody concentration too high | Test serial dilutions (1:1000, 1:2000, 1:5000) | Identifies optimal signal-to-noise ratio | |
| Endogenous peroxidase activity | Pre-treat membranes with 3% H₂O₂ for 10 minutes | Quenches endogenous HRP-like activity | |
| Inconsistent results | Buffer contamination | Prepare fresh buffers | Eliminates potential interfering substances |
| Secondary antibody cross-reactivity | Not applicable (HRP-conjugated primary) | N/A |
For immunohistochemistry applications:
Critical step: Quench endogenous peroxidase activity
For paraffin sections: 0.3% H₂O₂ in methanol for 30 minutes
For frozen sections: 0.1% H₂O₂ in PBS for 15 minutes
Optimization matrix approach:
Test combinations of:
Blocking agents (BSA, normal serum, commercial blockers)
Antibody dilutions (starting at the higher end of recommended range)
Incubation temperatures (4°C vs. room temperature)
Control experiments:
Include no-primary antibody controls
Use isotype controls (rabbit IgG at equivalent concentration)
When possible, include FMN1 knockdown samples
Research has established that FNBP4 interacts with the poly-proline-rich formin homology 1 (FH1) domain of FMN1 . This interaction can be studied using FMN1 Antibody, HRP conjugated through the following protocol:
Co-Immunoprecipitation Protocol:
Lysate preparation:
Lyse cells in non-denaturing buffer (e.g., 20 mM Tris-HCl pH 8.0, 137 mM NaCl, 1% NP-40, 2 mM EDTA) with protease inhibitors
Clear lysates by centrifugation (14,000 × g, 15 min, 4°C)
Pre-clearing:
Incubate lysate with Protein A/G beads for 1 hour at 4°C
Remove beads by centrifugation
Immunoprecipitation:
Add anti-FNBP4 antibody (5 μg) to pre-cleared lysate
Incubate overnight at 4°C with gentle rotation
Add Protein A/G beads and incubate for 2-4 hours at 4°C
Wash beads 4-5 times with lysis buffer
Detection:
Elute proteins by boiling in Laemmli buffer
Separate by SDS-PAGE
Transfer to membrane
Detect FMN1 using FMN1 Antibody, HRP conjugated (1:500 dilution)
Validation:
Perform reciprocal Co-IP using FMN1 antibody for immunoprecipitation and FNBP4 antibody for detection
Include appropriate controls (IgG control, input lysate)
Key scientific insights for experimental design:
Surface plasmon resonance studies have revealed the precise binding characteristics of the FMN1-FNBP4 interaction:
The binding affinity (KD) between FNBP4 and FMN1 is 1.84 nM
Association rate constant (ka): 3.31*106 M-1s-1
Furthermore, domain-specific analysis has shown that:
Only the WW1 domain of FNBP4 binds to FMN1, with a KD of 2 nM
The WW2 domain of FNBP4 does not interact with FMN1
Only the FH1 domain of FMN1 participates in this interaction; the FH2 domain does not
These insights should guide experimental design when analyzing FMN1-FNBP4 interactions.
FMN1 has been identified as a critical mediator of dendritogenesis in hippocampal neurons . To study this role using FMN1 Antibody, HRP conjugated, researchers can implement the following methodological approach:
Experimental design for FMN1-mediated dendritogenesis studies:
Neuronal culture preparation:
Prepare primary hippocampal neurons from E18-19 rat or mouse embryos
Plate neurons at intermediate density (100-150 cells/mm²) on poly-L-lysine coated coverslips
Culture in Neurobasal medium supplemented with B27 and GlutaMAX
Experimental manipulations:
Gain-of-function: Transfect neurons with FMN1-Ib expression vectors
Loss-of-function: Transfect neurons with FMN1-specific siRNAs (siRNA2 or siRNA3)
Include GFP co-expression for morphological analysis
Immunocytochemistry protocol:
Fix neurons with 4% PFA for 15 minutes at room temperature
Permeabilize with 0.1% Triton X-100 for 10 minutes
Block with 3% BSA + 5% normal goat serum for 1 hour
For dendrite visualization: Co-stain with anti-MAP2 antibody
For FMN1 detection: Use FMN1 Antibody, HRP conjugated (1:100-1:200)
Develop using DAB substrate or TSA amplification for fluorescent detection
Quantitative analysis:
Capture images at 20-40X magnification
Analyze:
Number of primary dendrites
Dendrite length and branching pattern
FMN1 localization along dendrites
Expected outcomes based on published research:
Overexpression of FMN1-Ib increases primary dendrite number by approximately 50% within 16 hours post-transfection
FMN1 knockdown reduces neurite number and counteracts the dendrite-promoting effects of Ngn3
FMN1-Ib localizes to the cytoplasm and is not found in neuronal nuclei
This experimental approach enables detailed investigation of FMN1's role in dendrite initiation and development, with the HRP-conjugated antibody providing sensitive detection of endogenous or overexpressed FMN1.
Research has revealed that FMN1 specifically increases the number of glutamatergic synaptic terminals without affecting GABAergic synapses . To investigate this phenomenon using FMN1 Antibody, HRP conjugated, implement this specialized protocol:
Materials and methods for synaptic analysis:
Neuronal culture preparation:
Culture hippocampal neurons at high density (250-300 cells/mm²) to ensure proper synaptic network formation
Maintain cultures for at least 10-14 days to allow synaptic maturation
Experimental manipulations:
Transfect neurons with FMN1-Ib expression vectors at DIV7-10
Include appropriate controls (empty vector or GFP-only expression)
For knockdown studies: Transfect FMN1-specific siRNAs
Immunocytochemistry for synaptic analysis:
Fix neurons with 4% PFA + 4% sucrose (to preserve synaptic structures)
Permeabilize with 0.2% Triton X-100 for 10 minutes
Block with 5% BSA + 5% normal goat serum for 1 hour
Triple immunostaining:
FMN1 Antibody, HRP conjugated (1:100-1:200)
Anti-VGlut1 antibody (marker for glutamatergic presynaptic terminals)
Anti-VGAT antibody (marker for GABAergic presynaptic terminals)
Use TSA amplification system to convert HRP signal to fluorescence
Quantitative analysis:
Capture high-resolution confocal z-stack images
Analyze:
Number of VGlut1-positive puncta per unit dendrite length
Number of VGAT-positive puncta per unit dendrite length
Calculate excitatory/inhibitory (E/I) synapse ratio
Co-localization of FMN1 with synaptic markers
Expected outcomes based on published data:
This methodology enables comprehensive analysis of FMN1's differential effects on excitatory versus inhibitory synapse formation, with implications for understanding neuronal circuit development and function.
Recent research has identified ciRNA-Fmn1 (a circular RNA derived from the FMN1 gene) as a key player in neuropathic pain regulation . Investigating the relationship between ciRNA-Fmn1 and FMN1 protein requires an integrated approach:
Comprehensive protocol for ciRNA-Fmn1/FMN1 protein studies:
Neuropathic pain model preparation:
Implement peripheral nerve injury model (e.g., chronic constriction injury or spared nerve injury)
Include sham-operated controls
Monitor pain behavior (mechanical allodynia, thermal hyperalgesia)
Tissue collection and processing:
Collect ipsilateral and contralateral spinal cord dorsal horn segments
Process for both RNA and protein extraction from parallel samples
For histological analysis: Prepare spinal cord sections (lumbar enlargement)
ciRNA-Fmn1 analysis:
Extract total RNA using methods optimized for circular RNA preservation
Perform RT-qPCR with divergent primers specific for ciRNA-Fmn1
RNA in situ hybridization to localize ciRNA-Fmn1 in tissue sections
FMN1 protein detection:
Western blot: Use FMN1 Antibody, HRP conjugated (1:500)
Immunohistochemistry:
Quench endogenous peroxidase activity
Incubate with FMN1 Antibody, HRP conjugated (1:200)
Develop with DAB substrate
Counterstain with hematoxylin
Correlation analysis:
Analyze temporal relationship between ciRNA-Fmn1 downregulation and FMN1 protein changes
Perform co-localization studies to determine cellular distribution
Investigate relationships with other key molecules (DHX9, UBR5, albumin)
Functional mechanistic studies:
Prevent ciRNA-Fmn1 downregulation (using RNA mimics or overexpression)
Assess effects on FMN1 protein levels
Analyze impact on UBR5-controlled albumin ubiquitination
Correlate molecular changes with pain behavior outcomes
Expected outcomes based on published research:
ciRNA-Fmn1 is significantly downregulated in ipsilateral dorsal horn neurons after peripheral nerve injury
This downregulation relates to decreased DHX9, which regulates ciRNA-Fmn1 production
Changes in ciRNA-Fmn1 affect its binding to ubiquitin ligase UBR5
This alters albumin ubiquitination and expression in the dorsal horn, contributing to pain hypersensitivity
This multifaceted approach allows researchers to elucidate the complex relationships between circular RNA and protein expression in neuropathic pain pathways.
To preserve the activity and specificity of FMN1 Antibody, HRP conjugated, researchers should adhere to these evidence-based storage and handling guidelines:
Storage conditions:
Aliquot upon receipt to minimize freeze-thaw cycles (each cycle can reduce activity by 10-15%)
For short-term storage (≤1 week), 4°C is acceptable
Buffer composition:
Most commercial FMN1 Antibody, HRP conjugated products are supplied in stabilizing buffers containing:
0.01M TBS (pH 7.4)
1% BSA (stabilizes protein)
0.03% Proclin300 (antimicrobial preservative)
Stability considerations:
HRP conjugates typically maintain >80% activity for 12 months when properly stored
Avoid exposure to strong oxidizing agents, which can inactivate HRP
Protect from prolonged light exposure, particularly UV light
Working solution handling:
Prepare working dilutions immediately before use
Do not store diluted antibody for extended periods
When removing from freezer, thaw at 4°C (never at high temperatures)
Centrifuge briefly after thawing to collect all material
Quality control testing:
Periodically verify antibody performance using positive control samples
Monitor for increased background or decreased signal intensity, which may indicate degradation
Consider including an HRP activity control in experiments
These practices will ensure maximum sensitivity and specificity of FMN1 Antibody, HRP conjugated throughout your research applications.
For rigorous quantitative analysis of FMN1 expression using FMN1 Antibody, HRP conjugated, researchers should implement technique-specific approaches:
Western Blot Densitometric Analysis:
Image acquisition parameters:
Capture images with a cooled CCD camera or digital imaging system
Ensure exposure time falls within the linear range of detection
Include a standard curve of recombinant FMN1 if absolute quantification is needed
Software-based quantification:
Use ImageJ, Image Studio, or similar analysis software
Define regions of interest (ROIs) for FMN1 bands (~158 kDa)
Subtract local background for each lane
Normalize to loading controls (GAPDH or total protein stain)
Data representation:
Express as relative fold change compared to control conditions
Present with appropriate statistical analysis (t-test, ANOVA)
Include error bars representing standard deviation or SEM
ELISA Quantification:
Standard curve preparation:
Sample interpolation:
Ensure sample readings fall within the linear portion of the standard curve
Dilute samples if readings exceed the upper limit
Account for dilution factors in final calculations
Quality control metrics:
Monitor intra-assay CV (<10%) and inter-assay CV (<15%)
Include duplicate or triplicate measurements for each sample
Record standard curve parameters (R² value should be >0.99)
Immunohistochemical Quantification:
Image acquisition standardization:
Use identical microscope settings across all samples
Capture multiple representative fields per sample
Include internal control regions within each section
Quantification approaches:
For DAB staining: Measure optical density using calibrated systems
Convert to H-score (calculation: [1 × (% cells 1+) + 2 × (% cells 2+) + 3 × (% cells 3+)])
For neuronal studies: correlate with morphological parameters
Advanced analysis for neuronal samples:
Measure FMN1 expression along dendrite length
Quantify co-localization with synaptic markers (Mander's coefficient)
Correlate expression with dendrite number or synaptic density
By implementing these quantification approaches, researchers can generate reliable, reproducible data on FMN1 expression across experimental conditions.
Understanding species cross-reactivity is essential when designing experiments with FMN1 Antibody, HRP conjugated across different model systems:
Species reactivity profile:
Epitope conservation analysis:
Most commercial FMN1 antibodies target epitopes within the region of amino acids 350-750 of the human FMN1 protein . Cross-species reactivity depends on conservation of these regions:
The immunogen range of 651-750/1419 amino acids in human FMN1 shows high conservation across mammals
The region corresponding to amino acids 350-495 of human FMN1 (NP_001096654.1) is also highly conserved
Experimental validation recommendations:
When using FMN1 Antibody, HRP conjugated in non-human models:
Perform preliminary validation with positive control samples from the target species
Include human samples as positive controls when possible
For unverified species, conduct pilot experiments with increasing antibody concentrations (1:300, 1:500, 1:1000)
Verify specificity using knockdown approaches in the species of interest
Species-specific considerations:
Rodent models (mouse/rat): Particularly useful for neuronal studies given the validated role of FMN1 in rodent hippocampal development
Human samples: Optimal for studying disease-relevant changes in FMN1 expression
Non-mammalian models: Limited validation data available; extensive testing recommended before use
Understanding these cross-species reactivity profiles enables appropriate experimental design and interpretation of results when studying FMN1 across different model systems.
FMN1 has been shown to interact with both actin and microtubule cytoskeletons through distinct domains . To investigate this dual functionality using FMN1 Antibody, HRP conjugated, researchers can implement this specialized experimental design:
Cytoskeletal co-localization analysis protocol:
Cell preparation:
Culture appropriate cell types (fibroblasts, epithelial cells, or neurons)
For neurons: use hippocampal cultures at DIV1-5 for developmental studies
Cytoskeletal disruption experiments:
Actin disruption: Treat cells with Cytochalasin D (1-5 μM, 30 min)
Microtubule disruption: Treat with Nocodazole (10 μM, 30 min)
Combined disruption: Sequential treatment with both agents
Include DMSO-treated controls
Triple immunostaining approach:
Fix cells with 4% PFA (preserves both cytoskeletal networks)
Permeabilize with 0.1% Triton X-100
Primary antibodies:
FMN1 Antibody, HRP conjugated (1:200) with TSA amplification
Anti-α-tubulin (microtubule marker)
Fluorescent phalloidin (F-actin marker)
Advanced imaging analysis:
Capture images using confocal microscopy with Z-stacks
Perform deconvolution to enhance resolution
Quantify co-localization using Pearson's or Mander's coefficients
Analyze FMN1 distribution following cytoskeletal disruption
Domain-specific analysis:
Research has shown that:
The peptide encoded by exon 2 of the Fmn1-Ib gene regulates localization to interphase microtubules
This localization is independent of the FH2 domain
Different regions of FMN1-Ib are responsible for associations with actin versus microtubule cytoskeletons
To investigate domain-specific functions:
Express wild-type FMN1-Ib or domain-specific mutants
Analyze differential localization to cytoskeletal structures
Evaluate effects on cytoskeletal organization and dynamics
This experimental approach enables detailed investigation of FMN1's dual role in coordinating actin and microtubule cytoskeletal networks.
Recent research has uncovered a novel pathway involving ciRNA-Fmn1, the ubiquitin ligase UBR5, and albumin in neuropathic pain . To investigate this complex interaction using FMN1 Antibody, HRP conjugated alongside other molecular tools, researchers can implement this comprehensive protocol:
Integrated experimental approach:
Neuropathic pain model:
Establish peripheral nerve injury model in rodents
Confirm pain phenotype (mechanical allodynia, thermal hyperalgesia)
Collect ipsilateral and contralateral spinal cord dorsal horn samples
Molecular expression analysis:
ciRNA-Fmn1: RT-qPCR with divergent primers
FMN1 protein: Western blot with FMN1 Antibody, HRP conjugated (1:500)
UBR5 and albumin (ALB): Western blot with respective antibodies
Protein-RNA interaction studies:
RNA immunoprecipitation (RIP):
Immunoprecipitate UBR5 protein
Extract bound RNA and detect ciRNA-Fmn1 by RT-qPCR
Compare binding efficiency between injured and control conditions
Protein-protein interaction analysis:
Co-immunoprecipitation:
Immunoprecipitate UBR5
Detect albumin by Western blot
Assess how ciRNA-Fmn1 levels affect this interaction
Ubiquitination assay:
Immunoprecipitate albumin
Detect ubiquitination using anti-ubiquitin antibodies
Compare ubiquitination levels across experimental conditions
Correlate with ciRNA-Fmn1 expression levels
Functional manipulation experiments:
Prevent ciRNA-Fmn1 downregulation (using viral vectors)
Knockdown UBR5 expression using siRNA
Assess effects on:
Albumin ubiquitination
Albumin protein levels
Pain behaviors
Expected molecular pathway based on published research:
Peripheral nerve injury leads to decreased DHX9, reducing ciRNA-Fmn1 levels
Reduced ciRNA-Fmn1 decreases its binding to UBR5
This reduces UBR5-mediated albumin ubiquitination
Decreased ubiquitination increases albumin levels in the dorsal horn
Elevated albumin contributes to neuropathic pain hypersensitivity
This integrated approach enables comprehensive investigation of the novel ciRNA-Fmn1/UBR5/albumin pathway in neuropathic pain, with potential therapeutic implications.
To investigate the complex interplay between FMN1, its binding partner FNBP4, and cytoskeletal structures, researchers can implement this advanced multidimensional analysis protocol:
Integrated experimental workflow:
Domain-specific binding characterization:
Express tagged constructs of FMN1 domains:
Full-length FMN1-Ib
FH1 domain only (amino acids 870-970)
FH2 domain only (amino acids 983-1466)
FH1-FH2 combined (amino acids 870-1466)
Express tagged constructs of FNBP4 domains:
Full-length FNBP4
WW1 domain only (amino acids 214-248)
WW2 domain only (amino acids 595-629)
Protein-protein interaction mapping:
Co-immunoprecipitation assays with domain-specific constructs
Surface plasmon resonance (SPR) analysis:
Cytoskeletal co-localization analysis:
Triple immunofluorescence staining:
FMN1 Antibody, HRP conjugated with TSA amplification
Anti-FNBP4 antibody
Cytoskeletal markers (tubulin and/or actin)
Super-resolution microscopy (STED or STORM) to visualize:
Spatial relationships between FMN1, FNBP4, and cytoskeletal elements
Domain-specific localization patterns
Functional perturbation experiments:
siRNA knockdown of FMN1 or FNBP4
Expression of dominant-negative domain constructs
Analysis of effects on:
Protein-protein interactions
Cytoskeletal organization
Cellular morphology (particularly in neurons)
Data integration and analysis:
Correlate binding affinities with cellular co-localization patterns
Map domain-specific interactions to cytoskeletal structures
Generate comprehensive interaction models