Histone H2A.XS139ph antibody (pAb)
Catalog Nos: 39117, 39118
RRID: AB_2793161
Application(s): DB, ICC, IF, WB
Reactivity: Human, Wide Range Predicted

Quantities: 100 µg, 10 µg
Purification: Protein A Chromatography
Host: Rabbit
Isotype: IgG
Molecular Weight: 15 kDa

Background: Histone H2AX phospho Ser139 (H2AX, H2A histone family member X) replaces conventional H2A in a subsetof nucleosomes. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries
that require DNA as a template. Histones thereby play a central role in transcriptional regulation, DNA repair, DNA replicationand chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also
called the histone code, and nucleosome remodeling. Histone H2AX is required for checkpoint-mediated arrest of cell cycle
progression in response to low doses of ionizing radiation, and for efficient repair of DNA double-strand breaks (DSBs),
specifically when modified by C-terminal phosphorylation.
Immunogen: This Histone H2AX phospho Ser139 antibody was raised against a peptide including phosphoserine 139 ofhistone H2AX.
Buffer: PBS containing 30% glycerol, 0.035% sodium azide. Sodium azide is highly toxic.
Application Notes:
Applications Validated by Active Motif:
ICC/IF: 1:500 dilution
WB*: 1:1,000 - 1:5,000 dilution
DB: 0.1 µg/ml*Note: many chromatin-bound proteins are not soluble in a low salt nuclear extract and fractionate to the pellet. Therefore, we
recommend a High Salt / Sonication Protocol when preparing nuclear extracts for Western Blot. Visit activemotif.com todownload the protocol.
Storage and Guarantee: Some products may be shipped at room temperature. This will not affect their stability orperformance. Avoid repeated freeze/thaw cycles by aliquoting items into single-use fractions for storage at -20°C for up to 2years. Keep all reagents on ice when not in storage. This product is guaranteed for 12 months from date of receipt.
This product is for research use only and is not for use in diagnostic procedures.

Application Key: ChIP = Chromatin Immunoprecipitation; FACS = Flow Cytometry; IF = Immunofluorescence; IHC = Immunohistochemistry; IP = Immunoprecipitation; WB = Western Blot

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Histone H2AX phospho Ser139 antibody tested by immunofluorescence.
HeLa cells stained with Histone H2AX phospho Ser139 antibody (1:500 dilution) using MAX
Stain™ Immunofluorescence Tools. The HeLa cells were blocked with MAXblock™ Blocking
Medium and stained with Histone H2AX phospho Ser139 antibody.
Panel A: Untreated HeLa cells.
Panel B: Cells fixed and stained 90 minutes after 3 Gy ionizing radiation treatment.
Top images: Cells were stained with DAPI.
Middle images: Same cells stained with Histone H2AX phospho Ser139 antibody.
Bottom images: Merge of both images above.
Images were made using Zeiss Axiovision with equivalent acquisition settings for directcomparison. Note Panel B-middle image, which shows intense nuclear clustering of ionizing
radiation-induced phosphorylation of Ser139 of H2AX. In contrast, Panel A-middle image shows
Histone H2AX phospho Ser139 antibody tested by immunofluorescence.
Etoposide-treated HeLa cells stained with Cat. No. 39117 (1:500 dilution, red) andcounterstained with DAPI (blue).

Histone H2AX phospho Ser139 antibody tested by Western blot.
Western blot: Nuclear extract of U2OS cells (20 µg per lane) probed with Histone H2AX
phospho Ser139 polyclonal antibody (1:500 dilution).
Lane 1: untreated cells
Lane 2: cells treated with camptothecin

Dot blot analysis was used to confirm the specificity of Histone H2A.
XS139phPeptides were spotted onto nitrocellulose at 2, 10 and 50 picomoles andprobed with the antibody at 0.1 ug/mL. Col. 1: Unmodified Peptide of Histone
H2AX. Col. 2: Peptide containing phospho-tyrosine 142 of Histone H2AX.
Col. 3: Peptide containing phospho-serine 139 of Histone H2AX.

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