COS-7 cell line: Origin and Characteristics

COS-7 Cell Line Background

COS (an abbreviation for CV-1 in Origin with SV40 genes) cells are a laboratory cell line derived in the 1960’s.  COS cells behave like fibroblasts, and were originally obtained by immortalizing CV-1 cells from the kidney of the African green monkey (Cercopithecus aethiops) using a SV40 virus that produces large T-antigen but does not replicate correctly. There are several varieties of COS cell lines in common use, including COS-1 and COS-7.  COS-7 was developed in the 1980’s via transformation with a mutant strain of SV40 that codes for the wild-type T-antigen.  These cell lines are used to study SV40 monkey viruses and as a common mammalian production cell for recombinant proteins, such as antibodies and signaling molecules.

COS-7 Origin

The COS-7 cell line was derived from kidney tissue of the African green monkey, Cercopithecus aethiops.  The cells themselves most resemble human fibroblast cells and are thus often called COS-7 monkey fibroblast or COS-7 fibroblast-like cells.  For added clarification, COS-7 cells are not primary cells.  In the early 1980’s, the COS-7 line was developed from the CV-1 line by Yakov Gluzman through transformation with a Simian Vacuolating Virus 40 (SV40), a virus that codes for the wild type virus T antigen. Using SV40 promoters, a vector can have substantial replication in COS cells using the large T-antigen.

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Copyright picture from Reproduced with permission from Altogen Biosystems.


COS-7 Cell Line Characteristics

The result of the transformation of CV-1 to create the COS-7 cell line was the expression of the SV40 T-antigen for which it retains and is susceptible to SV40, which grows lytically within the kidney cells. The replication of the A209 virus at 40°C is also permitted, as are SV40 mutants, as long as mutations (i.e. insertions, deletions, mutations) are in the early regions of the viral genome.  Thus, COS is an acronym for CV-1 in Origin, carrying SV40.

In culture, COS-7 cells characteristically display adherent growth to glass and plastic surfaces and are fibroblast-like.  The combination of fibroblastic-like growth and virus susceptibility make COS-7 a great choice for transfection experiments for DNA plasmids and mutations to the SV40 virus.  The SV40 virus continues to be utilized due to its putative involvement in human cancers.


Wikipedia article on Cos-7 cells – COS cells (Wikipedia)

Purchase Cos-7 cells – ATCC

In Vitro Cos-7 Transfection Reagent from Altogen Biosystems

In Vivo Cos7 siRNA transfection kit – In Vivo Transfection Kits

Generation of Stably Expressing Cell Lines in 28 Days

Stable RNAi Cell Line Generation: Stable Gene Knockdown

COS-7 Transfection Reagent (Kidney Cells, CRL-1651)