Detection of a contaminant cell culture line by restriction endonuclease cleavage patterns of mitochondrial DNA

Area of Science:

• Cell Biology
• Genetics
• Biotechnology

Background:

• Cell cultures are vital tools in biological research.
• Cross-contamination between cell lines is a significant issue, potentially compromising experimental results.
• HeLa cells are a widely used human cell line.

Purpose of the Study:

• To investigate a suspected contamination in a HeLa cell culture line.
• To identify the contaminating cell type.
• To evaluate the utility of mitochondrial DNA analysis for species identification in cell cultures.

Main Methods:

• Agarose gel electrophoresis of mitochondrial DNA digests using restriction endonucleases.
• Karyotypic analysis of cellular chromosomes.
• Analytical buoyant density centrifugation of total cellular DNA to detect specific DNA bands.

Main Results:

• Restriction endonuclease digestion profiles of mitochondrial DNA revealed the presence of non-human DNA.
• Karyotypic analysis confirmed the presence of mouse chromosomes.
• Buoyant density centrifugation identified the characteristic mouse satellite DNA band.

Conclusions:

• The investigated HeLa cell culture was contaminated with mouse cells.
• Mitochondrial DNA restriction endonuclease analysis is a sensitive and effective method for identifying the species of origin of cells in culture.
• This technique can serve as a crucial quality control measure for cell line authentication.