The Open Clinical Biochemistry Journal

2012, 5 : 33-39
Published online 2012 December 28. DOI: 10.2174/1874241601205010033
Publisher ID: TOCCHEMJ-5-33

Calibrators for Clinical Measurements of Phosphorylated H2AX in Patient Cells by Flow Cytometry

Aida Muslimovic , Pegah Johansson , Ulla Ruetschi and Ola Hammarsten
Department of Clinical Chem-istry and Transfusion Medicine Bruna straket 16, Sahlgrenska Academy at the University of Gothenburg, SE-41345 Gothenburg Sweden.

ABSTRACT

Agents that induce DNA double-strand breaks (DSBs), such as ionizing radiation, are frequently used in cancer therapy. H2AX is rapidly phosphorylated in response to DSBs and serves as a way to measure the extent of DSBs induced in patient cells. We have previously reported a flow cytometry-based method for measuring H2AX phosphorylation in pa-tient cells undergoing radiotherapy. To be able to implement measurement of H2AX phosphorylation in clinical practice, we have characterized calibrators for the flow cytometry analysis based on phosphopeptide-coated beads and fixed cells. The calibrator beads and fixed cells lost less than 11% of the signal after storage for 40 days under optimal conditions and were able to correct for day-to-day variation in method performance.

Keywords:

Calibrators, internal controls, correction.