Immunogen: The RPRML antibody is typically generated using synthesized peptides derived from specific regions of the human RPRML protein (e.g., amino acids 41–90) .
Reactivity: Validated for use in human, mouse, and rat models, with cross-reactivity observed in cow, guinea pig, dog, and horse tissues .
Host and Clonality: Produced in rabbit hosts as polyclonal IgG antibodies, ensuring broad epitope recognition .
Applications:
Antibodies are rigorously tested using cell lysates (e.g., RT-4, U-251 MG) and over-expression lysates to confirm specificity .
Reliability scores (e.g., "Enhanced" or "Supported") are assigned based on consistency across WB, IHC, and RNA-seq data .
In vitro studies: Overexpression of RPRML in gastric cancer cell lines (e.g., AGS) inhibited clonogenic capacity by 40–60% and reduced proliferation via G2/M cell cycle arrest () .
Biomarker potential: Circulating methylated RPRML DNA in plasma showed diagnostic utility for gastric cancer, with an AUC of 0.726 (56% sensitivity, 88% specificity) .
Zebrafish models: Rprml deficiency disrupted definitive hematopoiesis, reducing erythroid-myeloid progenitors (EMPs) and hematopoietic stem/progenitor cells (HSPCs) by 50–70% .
Mechanistic insight: Rprml regulates HSPC niche formation in the caudal hematopoietic tissue (CHT), critical for blood cell development .
KEGG: dre:100073335
UniGene: Dr.114261
RPRML (Reprimo-Like) is a protein related to Reprimo (RPRM), which functions as a downstream effector of p53-induced cell cycle arrest at the G2/M phase. The RPRM family is considered to include putative tumor suppressors that may be silenced in certain cancer types . RPRML is identified in UniProt as Q8N4K4 with Gene ID 388394 . Research indicates that RPRML expression patterns are tissue-specific and conserved across species, suggesting important biological functions . Understanding RPRML expression and regulation is particularly valuable for cancer research and cell cycle regulation studies.
Commercial RPRML antibodies vary in their properties and applications. For example, polyclonal antibody ABIN7096553 is produced in rabbits using a synthesized peptide derived from human RPRML as the immunogen . This antibody:
Detects endogenous levels of RPRML
Shows reactivity with human and mouse samples
Is suitable for ELISA applications (recommended dilution 1:20000-1:40000)
Is supplied in phosphate buffered saline (pH 7.4) with 150 mM NaCl, 0.02% sodium azide, and 50% glycerol
Other RPRML antibodies may target different epitopes. Some target the middle region (AA 41-90) and demonstrate cross-reactivity with multiple species including human, mouse, cow, guinea pig, rat, monkey, dog, and horse for Western blot applications .
Based on available data, RPRML antibodies can be utilized in various experimental applications:
The selection of the appropriate application depends on the specific research question and available samples. For all applications, proper validation and controls are essential to ensure reliable results .
Proper antibody validation is crucial for generating reliable research data. For RPRML antibodies, a multi-step validation approach is recommended:
Target specificity verification:
Use knockout/knockdown models as negative controls
Perform peptide competition assays using the immunizing peptide
Compare results with tissues known to express or lack RPRML
Use recombinant RPRML protein as a positive control
Application-specific validation:
For Western blot: Verify correct molecular weight band
For immunohistochemistry: Confirm expected tissue localization pattern
For ELISA: Establish a standard curve with recombinant protein
Cross-reactivity assessment:
Test against related proteins (especially RPRM)
Validate claimed cross-species reactivity with appropriate controls
According to comprehensive antibody characterization guidelines, validation should document that the antibody: (i) binds to the target protein; (ii) binds to the target protein in complex mixtures; (iii) does not bind to non-target proteins; (iv) performs as expected in the specific experimental conditions .
Successful Western blot detection of RPRML requires careful optimization:
Sample preparation:
Use appropriate lysis buffers containing protease inhibitors
Determine optimal protein loading (typically 20-50 μg total protein)
Ensure complete denaturation for SDS-PAGE
Gel electrophoresis and transfer:
Select appropriate percentage gel (10-15% recommended for RPRML)
Optimize transfer conditions for proteins in RPRML's molecular weight range
Consider semi-dry vs. wet transfer based on protein properties
Antibody incubation:
Test different blocking agents (BSA, non-fat milk)
Optimize primary antibody dilution through titration
Increase sensitivity with overnight incubation at 4°C
Signal detection and analysis:
Choose appropriate detection method based on expected expression level
Include proper loading controls for quantification
Perform densitometric analysis with multiple biological replicates
This methodological approach is consistent with best practices for antibody use in protein detection applications .
For comprehensive analysis of RPRML expression, researchers often complement protein studies with mRNA analysis:
RT-qPCR optimization:
Data analysis considerations:
Calculate relative expression using the ΔCT method against appropriate housekeeping genes
Present data as average relative expression ± SEM (for developmental studies) or as relative expression boxplots (for adult expression studies)
Use statistical programming tools (e.g., R package ggplot2) for data visualization
Technical validation:
Run technical replicates for each biological sample
Include no-template controls and no-RT controls
Validate primer efficiency using standard curves
This multi-level approach ensures reliable quantification of RPRML expression at the transcriptional level.
Researchers commonly encounter several challenges when working with RPRML antibodies:
| Issue | Potential Causes | Troubleshooting Approaches |
|---|---|---|
| Weak or no signal | Low target expression, antibody degradation, inappropriate detection method | Increase antibody concentration, use more sensitive detection systems, verify target expression in sample |
| High background | Insufficient blocking, non-specific binding, excessive antibody | Optimize blocking conditions, increase washing steps, titrate antibody, use different blocking agents |
| Multiple bands in Western blot | Cross-reactivity, protein degradation, post-translational modifications | Use freshly prepared samples with protease inhibitors, verify with another antibody targeting different epitope |
| Inconsistent results | Batch variation, protocol inconsistency, sample degradation | Use the same antibody lot when possible, standardize protocols, prepare fresh samples |
For polyclonal RPRML antibodies, background issues can be particularly challenging. Consider:
Pre-adsorption against non-specific proteins
Testing different secondary antibodies
Using highly cross-adsorbed secondary antibodies to reduce cross-reactivity
Antibody selection significantly impacts research reproducibility, with reports suggesting approximately 50% of commercial antibodies fail to meet basic characterization standards . For RPRML research:
Documentation and reporting:
Always report complete antibody information (vendor, catalog number, lot, dilution)
Document all validation steps performed
Share negative results and validation challenges with the community
Reproducibility considerations:
Use Research Resource Identifiers (RRIDs) to unambiguously identify antibodies
Consider recombinant antibodies when available for better consistency
Maintain detailed records of antibody performance across experiments
Cross-laboratory validation:
Compare results with multiple antibodies targeting different epitopes
Collaborate with other labs to verify findings with independent reagents
Participate in antibody validation initiatives when possible
The reproducibility crisis in antibody research has led to estimated financial losses of $0.4-1.8 billion per year in the United States alone , highlighting the critical importance of proper antibody selection and validation for RPRML studies.
Several advanced approaches can enhance the specificity of RPRML detection:
Recombinant antibody technology:
Multiplexed detection strategies:
Use multiple antibodies targeting different RPRML epitopes simultaneously
Combine antibody-based detection with nucleic acid analysis (e.g., RNA-Seq with proteomics)
Implement proximity ligation assays for enhanced specificity
Advanced imaging techniques:
Super-resolution microscopy for improved subcellular localization
Spectral imaging to reduce autofluorescence interference
Automated image analysis for quantitative assessment
Genetic tagging approaches:
CRISPR-mediated endogenous tagging of RPRML
Knock-in reporter systems for live cell imaging
Proximity-dependent labeling techniques (BioID, APEX)
These emerging methods can complement traditional antibody-based detection to provide more robust and specific information about RPRML expression and function.
Given that RPRM family members function as putative tumor suppressors , RPRML antibodies have valuable applications in cancer research:
Expression profiling across cancer types:
Compare RPRML levels between normal and malignant tissues
Correlate expression with clinical parameters and outcomes
Assess potential use as a diagnostic or prognostic biomarker
Mechanism investigation:
Study RPRML subcellular localization in cancer cells
Analyze changes in expression following treatment with chemotherapeutic agents
Investigate protein-protein interactions using co-immunoprecipitation
Functional studies:
Combine antibody detection with gain/loss-of-function experiments
Assess impact of RPRML modulation on cell cycle and apoptosis
Investigate relationship with p53 pathway components
Translational applications:
Develop tissue microarray studies for patient stratification
Explore potential as a therapeutic target
Assess correlation with response to specific treatments
Similar to studies with Reprimo in pituitary tumors , RPRML antibodies can help elucidate the role of this protein in various cancer types.
RPRML expression patterns appear to be conserved across species , but cross-species studies require careful planning:
Antibody cross-reactivity validation:
Empirically verify reactivity with each species of interest
Consider epitope conservation when selecting antibodies
Include appropriate positive controls from each species
Developmental considerations:
Expression patterns may vary across developmental stages
Use stage-appropriate controls when comparing species
Consider evolutionary differences in tissue-specific expression
Technical adaptations:
Optimize protocols for each species (fixation, antigen retrieval, etc.)
Use species-specific secondary antibodies
Adjust amplification methods based on expected expression levels
Data interpretation:
Acknowledge species differences in protein function and regulation
Consider evolutionary conservation of signaling pathways
Validate findings across multiple model organisms when possible
Studies in zebrafish have established protocols for analyzing rprm gene family expression , which may be adapted for cross-species comparisons.
Several emerging trends may enhance future RPRML antibody research:
Standardized validation initiatives:
Participation in community-wide antibody validation efforts
Implementation of minimum reporting standards for antibody characterization
Development of shared repositories for validation data
Technological advances:
Single-cell protein analysis techniques
Advanced multiplexing for simultaneous detection of multiple proteins
Integration of artificial intelligence for image analysis and quantification
Enhanced accessibility:
Open-source antibody sequences enabling local production
Improved data sharing across research groups
Centralized databases of antibody performance metrics
Systems biology integration:
Combined analysis of transcriptomics, proteomics, and functional data
Network analysis to position RPRML in broader signaling contexts
Computational prediction of protein interactions and functions
As antibody technology continues to evolve, large-scale initiatives like those focused on the human proteome will likely improve the quality and consistency of RPRML research tools .