CK19 antibodies detect a 40 kDa protein expressed in glandular/ductal epithelia (sweat glands, mammary ducts, bile ducts) and epithelial malignancies . Key applications include:
Thyroid carcinoma diagnosis (papillary and follicular subtypes)
Metastatic carcinoma detection in lymph nodes, bone marrow, and blood
Differentiation of hepatocellular carcinoma (CK19-negative) from cholangiocarcinoma or metastatic tumors (CK19-positive)
A53-B/A2.26: Achieves >90% pass rates in IHC with optimal epitope retrieval (HIER, pH 9.0) .
RCK108: Lower robustness (71% pass rate) but widely used; requires careful protocol optimization .
Thyroid Carcinoma: CK19 is overexpressed in 95% of papillary thyroid carcinomas and 50–60% of follicular carcinomas .
Breast Cancer: CK19 distinguishes luminal (MCF7, T47D) from basal-like subtypes (MDA-MB-231) .
Lung Cancer: Serum CYFRA 21-1 (CK19 fragment) serves as a prognostic biomarker .
| Method | Recommended Dilution | Key Clones |
|---|---|---|
| IHC | 1:100–1:51,200 | A53-B/A2.26, EP72 |
| Western Blot | 1:20,000–1:100,000 | EPR1579Y, BA17 |
| Flow Cytometry | 0.4 µg/10^6 cells | RCK108, A53-B/A2.26 |
| Cell Line | Subtype | CK19 Expression | Method |
|---|---|---|---|
| MCF7 | Luminal A | 76.2% (Flow) | IF, WB |
| T47D | Luminal A | 51.4% (Flow) | IF, WB |
| SKBR3 | HER2+ | 37.7% (Flow) | WB |
| MDA-MB-231 | Claudin-low | Negative | WB, IF |
| Clone | Optimal Rate | Pass Rate | Platform Compatibility |
|---|---|---|---|
| A53-B/A2.26 | 83% | 90% | Ventana, Leica Bond |
| RCK108 | 17% | 71% | Dako, Ventana |
| BA17 | 83% | 100% | Dako, Ventana |
When designing experiments involving CRK19 antibodies, what considerations should be taken into account to ensure specificity and sensitivity in detecting CRK19 proteins?
Specificity: Ensure the antibody is validated for its target specificity. This can be done by performing Western blot or immunoprecipitation experiments to confirm that the antibody binds only to CRK19.
Sensitivity: Optimize the concentration of the antibody and the detection method (e.g., fluorescence or chemiluminescence) to achieve the best signal-to-noise ratio.
Controls: Include negative controls (e.g., samples without CRK19 or using a non-specific antibody) to verify the specificity of the signal.
How can researchers address discrepancies in data from different CRK19 antibody experiments, particularly when comparing results across different laboratories or experimental conditions?
Standardization: Ensure that experimental conditions, such as antibody concentration, incubation times, and detection methods, are standardized across experiments.
Reproducibility: Repeat experiments multiple times to confirm findings and assess variability.
Inter-laboratory Comparison: Use common reference samples or standards to compare results between laboratories.
What are some advanced research questions related to CRK19 function that could be explored using CRK19 antibodies, and how might these questions be addressed experimentally?
Protein-Protein Interactions: Use co-immunoprecipitation assays with CRK19 antibodies to identify interacting proteins and understand CRK19's role in cellular processes.
Cellular Localization: Employ immunofluorescence microscopy to study CRK19's subcellular localization and dynamics.
Functional Knockdown/Knockout: Utilize CRISPR-Cas9 or RNA interference techniques to study the effects of CRK19 depletion on cellular processes.
What methodological approaches can be used to validate the specificity and efficacy of CRK19 antibodies for research applications?
Western Blot: Use Western blotting to confirm the antibody's ability to specifically recognize CRK19 in cell lysates.
Immunoprecipitation: Perform immunoprecipitation followed by mass spectrometry to validate the antibody's specificity for CRK19.
Immunofluorescence: Conduct immunofluorescence microscopy to verify the antibody's ability to detect CRK19 in fixed cells.
How can advanced techniques like single-molecule localization microscopy (SMLM) or super-resolution microscopy be applied to study CRK19 using CRK19 antibodies?
SMLM: Use techniques like photoactivated localization microscopy (PALM) or stochastic optical reconstruction microscopy (STORM) to achieve high-resolution imaging of CRK19 distribution at the nanoscale.
Super-Resolution Microscopy: Apply structured illumination microscopy (SIM) or stimulated emission depletion (STED) microscopy to study CRK19 localization and interactions with high spatial resolution.
What challenges might researchers face when interpreting data from CRK19 antibody experiments, and how can these challenges be addressed?
Background Signal: Minimize non-specific binding by optimizing antibody concentrations and using blocking agents.
Cross-Reactivity: Validate the antibody's specificity to ensure it does not cross-react with other proteins.
Quantification: Use quantitative methods (e.g., densitometry for Western blots) to accurately measure CRK19 levels.
How can CRK19 antibodies be used to compare CRK19 expression or function across different species, and what considerations are important for such studies?
Sequence Homology: Ensure that the CRK19 protein sequence is conserved across species to validate antibody cross-reactivity.
Experimental Conditions: Standardize experimental conditions to ensure comparable results.
Species-Specific Controls: Use species-specific controls to verify antibody specificity in each species studied.
How can CRK19 antibodies be integrated with other research tools (e.g., CRISPR-Cas9, RNAi) to enhance understanding of CRK19 function?
CRISPR-Cas9: Use CRISPR-Cas9 to knock out CRK19 and then apply CRK19 antibodies to study the effects on protein expression and cellular processes.
RNA Interference (RNAi): Employ RNAi to knock down CRK19 expression and use CRK19 antibodies to monitor changes in protein levels.
What are common issues encountered when using CRK19 antibodies, and how can these issues be troubleshooted?
Non-Specific Binding: Increase blocking agent concentration or use a different blocking agent to reduce background.
Low Signal: Optimize antibody concentration, incubation time, or detection method to enhance signal.
Cross-Reactivity: Validate antibody specificity using Western blot or immunoprecipitation.
What future research directions involving CRK19 antibodies might provide new insights into CRK19 function and its role in biological processes?
Single-Cell Analysis: Apply single-cell techniques (e.g., single-cell Western blot) to study CRK19 expression variability at the single-cell level.
In Vivo Studies: Use CRK19 antibodies in in vivo models to study CRK19's role in disease processes or development.
Proteomics Integration: Integrate CRK19 antibody data with proteomics approaches to understand CRK19's interactions and post-translational modifications.