53bp1
53bp1 - Related Videos
05:34
Dual Immunofluorescence of γH2AX and 53BP1 in Human Peripheral Lymphocytes
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Cited by 5 •
2023
This protocol presents a method to assess the formation and repair of DNA double-strand breaks through the simultaneous detection of γH2AX and 53BP1 foci in interphase nuclei of bleomycin-treated human peripheral lymphocytes.
10:47
Immunofluorescence Microscopy of γH2AX and 53BP1 for Analyzing the Formation and Repair of DNA Double-strand Breaks
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Cited by 40 •
2017
This manuscript provides a protocol for the analysis of DNA double-strand breaks by immunofluorescence microscopy of γH2AX and 53BP1.
10:44
Laser Microirradiation to Study In Vivo Cellular Responses to Simple and Complex DNA Damage
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Cited by 12 •
2018
The goal of this protocol is to describe how to use laser microirradiation to induce different types of DNA damage, including relatively simple strand breaks and complex damage, to study DNA damage signaling and repair factor assembly at damage sites in vivo.
05:23
Immunofluorescence Microscopy for the Analysis of DNA Double-Strand Breaks
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2025
In this video, we describe the immunofluorescence microscopy technique to detect specific DNA damage response proteins localized at the sites of DNA double-strand breaks in human mononuclear cells. The proteins are recognized by specific primary antibodies, which in turn bind to fluorophore-tagged secondary antibodies that fluoresce during microscopic visualization, enabling visualization of the proteins as distinct fluorescent foci within the cell nuclei.
05:42
Immunofluorescence-Based Visualization of DNA Repair Protein Interactions
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2025
In this video, we describe the immunofluorescence method to visualize the localization of the DNA repair proteins γH2AX and 53BP1 at the sites of double-strand DNA breaks in irradiated cell nuclei.
FAQs
These modified histones provide chromatin-associated recognition sites around DNA double-strand breaks. By binding H4K20me2 and ubiquitinated H2AK15, 53BP1 accumulates near damaged chromosome ends and creates a platform for downstream repair factors. This localization is important because it connects the chromatin state surrounding a break with the subsequent control of DNA-end processing.
53BP1 helps protect damaged DNA ends from excessive 5′-to-3′ resection, the processing step that can produce substrates for homologous recombination. Limiting that resection generally supports non-homologous end joining instead. The balance is not absolute, because the influence of 53BP1 depends on the cell-cycle context and the repair conditions surrounding the break.
The relationship between 53BP1 and repair pathway choice changes across cell-cycle contexts. Its protection of DNA ends can promote non-homologous end joining in many settings, whereas homologous recombination depends on access to appropriately processed DNA ends. Consequently, interpreting a 53BP1 signal requires considering both the damage response and the cellular context in which the break occurs.
53BP1 immunofluorescence visualizes its accumulation in nuclear foci associated with DNA double-strand breaks. The presence and distribution of these foci provide a readout of DNA damage signaling rather than a complete measurement of repair success. Examining the signal over time can therefore help researchers assess how damage-associated responses develop and resolve.
Focus quantification converts the immunofluorescence pattern into a measurable readout that can be compared across experimental conditions or time points. Changes in focus abundance or persistence can indicate differences in DNA damage signaling and the progression of repair kinetics. This makes the approach useful for evaluating how cells respond to damage without treating focus counts as a direct pathway measurement.
Studies of genome stability, replication stress, cancer biology, radiosensitivity, and targeted genome editing can use 53BP1 immunofluorescence or focus quantification. In these settings, the assay supplies information about damage signaling and repair behavior, helping investigators compare cellular responses or experimental conditions. Its value comes from linking a visible chromatin-associated response with broader questions about chromosome repair.