Abstract: A carrier plate and a liquid sample are provided for the use of a single cell gel electrophoresis device for screening a subject for at least a DNA-damage, in particular a specific DNA-damage, in relation to a predisposition for and/or the presence of a disease. The liquid sample has cells of the subject. A single cell gel electrophoresis on the sample of the subject is performed by positioning the sample accommodated on the carrier plate in the generated homogenous electrical field and controlling strength and direction of the electrical field while the sample is positioned in the gel electrophoresis device. The DNA-damage is determined with a high reproducibility, with a coefficient of variation (CV) of 15% or less, in particular 10% or less, in particular 5% or less.

Abstract: A carrier plate, which is used within an electrophoresis process, and to a holding device tailored to the carrier plate, the carrier plate having a region with a magnetic property and a positioning device. The magnetic property is designed to fix the carrier plate in the laboratory device. The positioning device is designed to guarantee a position of the carrier plate in the laboratory device.

Abstract: A gel electrophoresis apparatus for single cell gel electrophoresis, including a chamber for receiving a gel electrophoresis buffer, a functional cover for closing the chamber, at least one pair of electrodes for generating a homogeneous electric field in the chamber and at least one retaining element for receiving and positioning at least one support plate. The at least one retaining element positions the at least one support plate in the homogeneous electric field generated by the at least one pair of electrodes.