Sad apoptotic tumor cell. :(
These tumor cells were treated with a cytostatic agent. The stronger the signal (green fluorescence), the more destroyed the cell.
Background:
A DNA double-strand break in the cell triggers the kinase Ataxia Telangiectasia Mutated which in turn phosphorylates the serine-139 residue of the histone subunit H2AX. The p53 binding protein 53BP1 binds to the phosphorylated H2AX (γH2AX) and regulates the repair of DNA double-strand breaks. γH2AX and 53BP1 can be tagged by appropriate antibodies so that individual double-strand breaks can be detected via secondary fluorochrome-labeled antibodies. The thus obtained fluorescent signal is visible as foci (pixel).
https://www.medipan.de/en/innovations/tests/aklidesr-nuk-human-lymphocyte-tests/