How do I confirm the presence of cross-contamination in my cell cultures?

The presence of cross-contamination in cell cultures can be confirmed using karyotype analysis, DNA fingerprinting or isotype analysis. Karyotype analysis involves the examination of stained chromosomes. DNA fingerprinting is based on determining the nucleotide sequences of certain areas of DNA. Isotype analysis uses band patterns to detect the species-specific differences in the dynamics and structure of individual isoforms.