The correct answer is (B) Sf9, a widely used insect cell line derived from Spodoptera frugiperda (fall armyworm) ovarian tissue, ideal for baculovirus expression systems in recombinant protein production.​

Correct Answer

Sf9 stands out as the only insect cell line among the options. Originating from the IPLB-Sf-21-AE line, Sf9 cells support suspension culture and excel in high-density growth, viral infection susceptibility, and protein expression via baculoviruses. They feature a 27-hour doubling time and mixed diploid/tetraploid karyotype, making them a staple in biotech research.​

HEK 293 Explanation

HEK 293 is a human embryonic kidney cell line transformed with adenovirus DNA, commonly used for mammalian protein expression and viral vector production, not insects. It supports transient transfections but lacks insect-specific post-translational modifications like those in Sf9.​

DH5α Explanation

DH5α refers to a strain of Escherichia coli bacteria, an E. coli competent cell line for cloning and plasmid propagation in prokaryotic systems, with no eukaryotic or insect cell properties. It excels in DNA manipulation but cannot perform complex glycosylation like insect cells.​

CHO Explanation

CHO (Chinese Hamster Ovary) cells derive from hamster ovaries and serve as a mammalian host for biopharmaceutical production, including monoclonal antibodies, due to human-like glycosylation. Unlike Sf9, they are not insect-derived and require different media and conditions.​