HEK293 cells, or human embryonic kidney 293 cells, are a widely used immortalized cell line in cell and molecular biology research. The HEK293 cell line was derived in the early 1970s by transfecting human embryonic kidney cells with sheared adenovirus 5 DNA. The resulting cells contained a portion of the adenovirus genome, which provided the cells with their immortalization properties.
Cytogenetics is the study of chromosomes, their structure, function, and behavior in relation to gene inheritance, organization, and expression. In the context of HEK293 cells, understanding their cytogenetics is essential for determining the stability and characteristics of the cell line, which can impact experimental outcomes and the production of recombinant proteins or viral vectors.
HEK293 cells are known to exhibit an abnormal karyotype, which means they have an abnormal number and/or structure of chromosomes. The normal human karyotype consists of 46 chromosomes, including 22 pairs of autosomes and one pair of sex chromosomes (XX in females, XY in males). However, HEK293 cells typically show a hyperdiploid karyotype, with a chromosome count ranging from 60 to 70, and have been reported to contain both human and adenoviral DNA sequences.
Due to the chromosomal instability of HEK293 cells, the karyotype can change over time and with continuous passaging. This instability can potentially affect gene expression, cell behavior, and the reproducibility of experiments. It is crucial to monitor the characteristics of the cell line and passage number to ensure consistency in experimental results.
Despite their abnormal karyotype, HEK293 cells remain a popular choice for various research applications, including gene expression studies, protein production, and viral vector production, due to their high transfection efficiency, rapid growth, and ease of maintenance in culture.