COS-7 Cells - 40X Magnification - Confocal Microscopy

COS are

fibroblast A fibroblast is a type of cell (biology), biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework (Stroma (tissue), stroma) for animal Tissue (biology), tissues, and plays a critical role in wound ...

-like cell lines derived from monkey kidney tissue. COS cells are obtained by immortalizing CV-1 cells with a version of the SV40 virus that can produce

large T antigen The large tumor antigen (also called the large T-antigen and abbreviated LTag or LT) is a protein encoded in the genomes of polyomaviruses, which are small double-stranded DNA viruses. LTag is expressed early in the infectious cycle and is essent ...

but has a defect in genomic replication. The CV-1 cell line in turn was derived from the kidney of the

African green monkey ''Chlorocebus'' is a genus of medium-sized primates from the family of Old World monkeys. Six species are currently recognized, although some people classify them all as a single species with numerous subspecies. Either way, they make up the ent ...

. The acronym "COS" is derived from the cells being CV-1 (simian) in Origin, and carrying the SV40 genetic material. Three COS lines were created (COS-1, COS-3 and COS-7), of which two are commonly used (COS-1 and COS-7).

Applications

The COS cell lines are often used by biologists when studying the monkey virus SV40. Cells from these lines are also often transfected to produce recombinant proteins for molecular biology, biochemistry, and cell biology experiments. When an expression construct with an SV40 origin of replication is introduced into COS cells, the vector can be replicated substantially by the

. These COS cells are genetically modified to produce the T antigen from their own genome.

References

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External links

Cellosaurus entry for COS-1Cellosaurus entry for COS-3Cellosaurus entry for COS-7
Monkey cell lines