Acetyl-Histone H2A (Lys9) Antibody
Product Specs
Q&A
What does Acetyl-Histone H2A (Lys9) Antibody specifically detect and why is it important?
Acetyl-Histone H2A (Lys9) antibody specifically recognizes histone H2A only when acetylated at lysine 9, a post-translational modification crucial for chromatin structure regulation . This highly specific antibody targets a key marker of active chromatin regions, enabling researchers to investigate epigenetic regulatory mechanisms . The modification occurs on histone H2A proteins, which have an observed molecular weight of approximately 14-16 kDa . Histone H2A acetylation at lysine 9 plays a vital role in the dynamic regulation of gene expression and chromatin accessibility, making it an important target for understanding transcriptional control mechanisms .
What applications are validated for Acetyl-Histone H2A (Lys9) antibodies?
Acetyl-Histone H2A (Lys9) antibodies have been validated for multiple experimental applications, with specific validation dependent on the particular antibody product. The following table summarizes the validated applications across different antibody products:
These validated applications make the antibodies versatile tools for investigating H2A Lys9 acetylation in multiple experimental contexts, from protein expression analysis to cellular and tissue localization studies .
What are the recommended dilutions for different experimental applications?
The optimal dilution varies depending on the specific application and antibody product. Based on validated protocols, the following dilution ranges are recommended:
| Application | Recommended Dilution Range |
|---|---|
| Western Blot (WB) | 1:1000-1:10000 |
| Immunohistochemistry (IHC) | 1:250-1:1000 |
| Immunofluorescence (IF)/ICC | 1:200-1:800 |
| Dot Blot | 1:10-1:100 |
It is strongly recommended that researchers titrate the antibody in their specific experimental system to determine optimal dilution, as sample type and preparation method can significantly impact antibody performance . For Western blotting applications, starting with a 1:2000 dilution is generally appropriate, while immunohistochemistry typically requires a more concentrated antibody solution .
What species reactivity do these antibodies demonstrate?
The species reactivity profile varies among different Acetyl-Histone H2A (Lys9) antibody products. Most products show confirmed reactivity with human samples, while some extend to mouse and rat samples as well . Specifically:
When selecting an antibody for your research, it is essential to choose one with validated reactivity to your species of interest to ensure reliable experimental results .
How should these antibodies be stored to maintain optimal functionality?
Proper storage is critical for maintaining antibody functionality and specificity. All the Acetyl-Histone H2A (Lys9) antibodies examined share similar storage requirements . The antibodies should be stored at -20°C, where they typically remain stable for one year after shipment . They are supplied in liquid form, generally in PBS buffer containing 0.02% sodium azide as a preservative and 50% glycerol to prevent freezing damage at pH 7.3 . Importantly, for the antibodies formulated in this manner, aliquoting is unnecessary for -20°C storage, which simplifies laboratory handling procedures .
How can Acetyl-Histone H2A (Lys9) antibodies be optimized for chromatin immunoprecipitation (ChIP) experiments?
While ChIP is not explicitly listed among the validated applications in the search results, researchers can adapt these antibodies for ChIP experiments with appropriate optimization. When implementing ChIP protocols with Acetyl-Histone H2A (Lys9) antibodies, several critical factors must be considered. First, perform antibody titration experiments to determine the optimal antibody-to-chromatin ratio, typically starting with 2-5 μg of antibody per ChIP reaction and adjusting based on preliminary results .
Cross-linking conditions are particularly important for histone modifications – standard 1% formaldehyde for 10 minutes at room temperature works for most applications, but optimization may be necessary . Include appropriate controls in each experiment: (1) a positive control antibody targeting abundant modifications (such as H3K4me3), (2) a negative control IgG from the same species as your primary antibody, and (3) positive and negative control genomic regions where H2A Lys9 acetylation is known to be present or absent, respectively .
For sonication, aim for chromatin fragments between 200-500 bp for optimal resolution, and validate fragment size by agarose gel electrophoresis . When analyzing ChIP-seq data involving H2A Lys9 acetylation, correlate findings with other active chromatin marks and transcriptional data to establish functional relationships .
What controls should be included when using Acetyl-Histone H2A (Lys9) antibodies in Western blot experiments?
When conducting Western blot experiments with Acetyl-Histone H2A (Lys9) antibodies, include multiple controls to ensure reliable and interpretable results. Positive controls should include samples known to contain high levels of the acetylation mark, such as histone extracts from cells treated with histone deacetylase (HDAC) inhibitors like Trichostatin A (TSA) . The search results specifically mention TSA-treated NIH/3T3 cells as a positive control for the 83041-1-RR antibody .
Negative controls should include: (1) untreated cells that have lower levels of acetylation, (2) samples treated with histone acetyltransferase (HAT) inhibitors, and (3) competition assays where the antibody is pre-incubated with the immunizing peptide before Western blotting . Additionally, include a loading control antibody targeting total H2A or another stable protein to normalize for loading variations .
For antibody validation, consider performing peptide array experiments with modified and unmodified peptides to confirm specificity against the acetylated Lys9 residue versus other potential H2A acetylation sites . This rigorous control scheme helps distinguish specific signals from background and validates the antibody's specificity for the acetylated Lys9 epitope.
How do different fixation and permeabilization methods affect detection of Acetyl-Histone H2A (Lys9) in immunofluorescence experiments?
After fixation, permeabilization is critical for antibody access to nuclear antigens. A brief treatment with 0.2-0.5% Triton X-100 in PBS for 5-10 minutes is commonly effective . For challenging samples, consider a dual approach: fix with paraformaldehyde followed by a brief methanol treatment to enhance permeabilization while preserving morphology .
Epitope masking can occur due to protein-protein interactions or chromatin compaction. To improve epitope accessibility, incorporate an antigen retrieval step: for paraffin-embedded sections, heat-induced epitope retrieval using TE buffer (pH 9.0) is recommended, though citrate buffer (pH 6.0) may be used as an alternative . For cultured cells, a brief treatment with 0.1% SDS can sometimes enhance detection of histone modifications by partially denaturing chromatin structure .
What experimental approaches can distinguish different histone H2A acetylation marks and assess their functional relationships?
To establish functional relationships between H2A Lys9 acetylation and other histone modifications, sequential ChIP (re-ChIP) experiments can reveal co-occurrence of different modifications on the same nucleosomes . Combine this with next-generation sequencing to map genome-wide distributions and identify regions where modifications co-localize or are mutually exclusive .
Functional studies using HDAC inhibitors (like Trichostatin A) or HAT inhibitors can reveal causal relationships between acetylation status and biological outcomes . For mechanistic insights, employ CRISPR-based approaches to recruit specific HATs or HDACs to genomic loci and observe effects on H2A Lys9 acetylation status, chromatin accessibility, and gene expression . Correlation with transcriptomic data (RNA-seq) can establish relationships between H2A Lys9 acetylation patterns and gene expression changes during biological processes .
How does Acetyl-Histone H2A (Lys9) distribution change during different cellular processes?
The distribution and dynamics of Acetyl-Histone H2A (Lys9) vary significantly across different cellular processes. During cell cycle progression, H2A Lys9 acetylation patterns undergo dynamic changes, with levels typically decreasing during mitosis when chromatin is highly condensed and increasing during S phase when DNA replication occurs . This dynamic pattern can be visualized using immunofluorescence microscopy with Acetyl-Histone H2A (Lys9) antibodies in synchronized cell populations .
In cellular differentiation processes, H2A Lys9 acetylation redistributes across the genome as gene expression programs are remodeled . This can be monitored using ChIP-seq at different time points during differentiation, revealing how acetylation patterns correlate with changes in developmental gene expression . During cellular stress responses, such as DNA damage, H2A Lys9 acetylation may be rapidly modified at specific genomic regions involved in the stress response pathways .
For studying these dynamic changes, live-cell imaging techniques using FRET-based acetylation sensors can provide temporal resolution not possible with fixed-cell approaches . Additionally, for genome-wide studies, CUT&RUN or CUT&Tag methods offer higher signal-to-noise ratios than traditional ChIP-seq, potentially revealing subtle changes in H2A Lys9 acetylation distribution during cellular transitions .
How can weak or non-specific signals be troubleshooted when using Acetyl-Histone H2A (Lys9) antibodies?
When encountering weak or non-specific signals with Acetyl-Histone H2A (Lys9) antibodies, systematic troubleshooting is essential. For weak signals in Western blot applications, first optimize protein extraction methods to ensure preservation of acetylation marks – use fresh samples and include HDAC inhibitors (e.g., sodium butyrate or Trichostatin A) in extraction buffers . Consider increasing antibody concentration within the recommended ranges (1:1000-1:5000 for 82823-2-RR or 1:2000-1:10000 for 83041-1-RR) .
For non-specific signals, extend blocking time (1-2 hours at room temperature with 5% BSA) and increase washing duration and volume (at least 3×10 minutes with TBST) . Optimize secondary antibody dilution and consider using a more specific secondary antibody with minimal cross-reactivity . If background persists, pre-absorb the primary antibody with cell/tissue lysate lacking the target protein .
For immunohistochemistry applications, antigen retrieval conditions significantly impact signal quality. The 83041-1-RR antibody documentation specifically recommends using TE buffer (pH 9.0) for antigen retrieval, with citrate buffer (pH 6.0) as an alternative . Optimize retrieval time and temperature based on your specific tissue type and fixation conditions .
What sample preparation methods best preserve Acetyl-Histone H2A (Lys9) for different experimental approaches?
Effective sample preparation is crucial for maintaining the integrity of Acetyl-Histone H2A (Lys9) modification across different experimental approaches. For cell and tissue lysates intended for Western blotting, harvest cells directly in SDS loading buffer containing HDAC inhibitors (5-10 mM sodium butyrate) and protease inhibitors to immediately denature proteins and preserve acetylation marks . Alternatively, use histone extraction protocols with acid extraction (0.2N HCl or 0.4N H2SO4) followed by TCA precipitation to obtain enriched histone fractions with preserved modifications .
For immunofluorescence, fix cells quickly after experimental treatments – delays can result in significant changes to acetylation patterns due to stress responses . Use 4% paraformaldehyde fixation for 10-15 minutes followed by permeabilization with 0.2% Triton X-100, and include sodium butyrate (5 mM) in all buffers until the primary antibody incubation step .
For tissue samples intended for immunohistochemistry, perfusion fixation (when possible) provides superior preservation of histone modifications compared to immersion fixation . Limit fixation time to prevent excessive crosslinking that might mask epitopes, and process tissues promptly after collection . For formalin-fixed paraffin-embedded samples, antigen retrieval with TE buffer (pH 9.0) significantly improves detection of Acetyl-Histone H2A (Lys9), as specifically recommended for antibody 83041-1-RR .
How can Acetyl-Histone H2A (Lys9) antibodies be utilized in disease-related epigenetic research?
Acetyl-Histone H2A (Lys9) antibodies serve as valuable tools in investigating epigenetic dysregulation in various diseases. In cancer research, these antibodies can be used to map genome-wide changes in H2A Lys9 acetylation patterns between normal and malignant tissues, potentially identifying epigenetically dysregulated oncogenes or tumor suppressors . This approach can be combined with transcriptomic analysis to correlate acetylation changes with altered gene expression profiles in disease states .
For neurological disorders, where epigenetic mechanisms are increasingly recognized as important factors, these antibodies can be applied to brain tissue sections using immunohistochemistry (with antibody 83041-1-RR at 1:250-1:1000 dilution) to investigate region-specific alterations in H2A Lys9 acetylation patterns . In chromatin-based disorders, ChIP-seq using these antibodies can reveal genome-wide redistribution of H2A Lys9 acetylation that may contribute to pathological gene expression patterns .
For drug discovery research, Acetyl-Histone H2A (Lys9) antibodies are valuable for screening compounds targeting histone acetyltransferases or deacetylases . Western blot analysis (using antibodies at 1:1000-1:10000 dilution) can quantify changes in global H2A Lys9 acetylation levels in response to epigenetic modulator compounds . Additionally, these antibodies can be used to evaluate the efficacy and specificity of HDAC inhibitors like Trichostatin A, which has been demonstrated to increase H2A Lys9 acetylation in NIH/3T3 cells, as noted in the validation data for antibody 83041-1-RR .
What strategies can optimize multiplexed detection of Acetyl-Histone H2A (Lys9) with other histone modifications?
Multiplexed detection of Acetyl-Histone H2A (Lys9) alongside other histone modifications provides comprehensive insights into chromatin regulation. For immunofluorescence approaches, select primary antibodies from different host species (e.g., rabbit anti-Acetyl-Histone H2A (Lys9) with mouse anti-H3K27me3) to allow simultaneous detection with species-specific secondary antibodies . When antibodies are from the same species, implement sequential immunostaining with complete blocking between rounds and use directly conjugated primary antibodies to avoid cross-reactivity .
For flow cytometry applications, optimize fixation and permeabilization conditions to preserve nuclear architecture while allowing antibody access to multiple epitopes . Standardize using compensation controls with single-stained samples to correct for spectral overlap between fluorophores . For biochemical approaches, sequential immunoprecipitation (Re-ChIP) can identify genomic regions where H2A Lys9 acetylation co-occurs with other histone modifications on the same nucleosomes .
When designing multiplexed experiments, consider potential epitope masking – the binding of one antibody might sterically hinder access to nearby epitopes, particularly for modifications on the same histone tail . In such cases, careful titration of antibody concentrations and application sequence becomes crucial . For truly comprehensive analysis, combine antibody-based methods with mass spectrometry, which can simultaneously identify and quantify multiple histone modifications without the limitations of epitope accessibility or antibody cross-reactivity .
