Background
DNA damage, due to environmental factors and normal metabolic processes inside the cell, occurs at a
rate of 1,000 to 1,000,000 molecular lesions per cell per day. While this counts for only a small part of
the human genome's approximately 6 billion bases (3 billion base pairs), unrepaired lesions to critical
genes can impede a cell's ability to carry out its function and appreciably increase the likelihood of
cancer.
The comet assay, or single cell gel electrophoresis assay (SCGE), is a common technique for
measurement of DNA damage in individual cells. Under an electrophoretic field, damaged cellular DNA
(containing fragments and strand breaks) is separated from intact DNA, yielding a classic “comet tail”
shape under the microscope. Extent of DNA damage is usually visually estimated by comet tail
measurement; however, image analysis software is also available for measuring various parameters.
The OxiSelect™ Comet Assay Control Cells are provided as a set; the set containing vials of healthy,
untreated cells and DNA damaged, Etoposide-treated cells. These cells are intended for use as controls in
the Cell Biolabs’ OxiSelect™ Comet Assay under alkaline electrophoresis conditions.
Application
Cell Biolabs’ OxiSelect™ Comet Assay Control Cells are designed for use in a single cell gel
electrophoresis assay (SCGE) for simple evaluation of cellular DNA damage (under alkaline conditions).
First, individual cells are mixed with molten agarose before application to the OxiSelect™ Comet Slide.
These embedded cells are then treated with a lysis buffer and alkaline solution, which relaxes and
denatures the DNA. Finally, the samples are electrophoresed in a horizontal chamber to separate intact
DNA from damaged fragments. Following alkaline electrophoresis, the samples are dried, stained with a
DNA dye, and visualized by epifluorescence microscopy. Under these conditions, the damaged DNA
(containing cleavage and strand breaks) will migrate further than intact DNA and produce a “comet tail”
shape (see Figure 1). For a complete protocol, refer to Cell Biolabs’ OxiSelect™ Comet Assay Kit insert
(STA-350).
Related Products
1. STA-350: OxiSelect™ 3-Well Comet Assay Kit (5 Slides, 15 Assays)
2. STA-351: OxiSelect™ 3-Well Comet Assay Kit (25 Slides, 75 Assays)
3. STA-352: OxiSelect™ 3-Well Comet Assay Slides (5 Slides)
4. STA-353: OxiSelect™ 3-Well Comet Assay Slides (25 Slides)
5. STA-355: OxiSelect™ 96-Well Comet Assay Kit (1 Slide, 96 Assays)
6. STA-356: OxiSelect™ 96-Well Comet Assay Slide (1 Slide)