The transfection of plasmids into mammalian cells directly incorporates genetic material into the genome to form a stable transfection. Stable transfection is used to create cell populations that will continue to express the genetic characteristics of the foreign material and then pass it on to the offspring. In order to achieve stable transfection, there should be selective pressure to force cells to integrate plasmid DNA into the genome. Reporter genes are usually used to easily monitor the transfection efficiency and expression levels in cells. Synbio Technologies provides a variety of reporter gene expression vectors to meet the screening needs of different cell lines and efficiently screen expression according to cell-specific screening conditions.
Fluorescent Proteins, Promoters, and Selectable Markers Selection
Different promoters have different activation activities in different cells. For example, in hematopoietic stem cells, SFFV has much better activation activity than CMV. There are also differences in tissue-specific expression. AAT is highly expressed in liver tissues and weakly expressed in other tissues. hSyn is highly expressed in nerve cells and weakly expressed in other tissues. Synbio Technologies provide a variety of fluorescent proteins, promoters, and mammalian expression vectors with selectable markers to meet the needs of cell-specific screening.
Schematic diagram of mammalian cell expression vector
Selectable markers in mammalian cells work similarly to that in bacteria. A table of the most commonly used selectable markers are listed below:
Name
Gene Conferring Resistance
Cell Types
Mode of Action
Blasticidin
bsd
HEK293, CHO, HeLa, COS-1NIH3T3
Inhibits termination step of translation
G418/Geneticin
neo
HEK293, CHO,HeLa, NIH3T3, Jurkat T cells
Blocks polypeptide synthesis at 80S; inhibits chain elongation
Hygromycin B
hygB
CHO, HeLa, NIH3T3, Jurkat T cells
Blocks polypeptide synthesis at 80S; inhibits chain elongation
Puromycin
pac
HEK293, HeLa, Jurkat T cells
Inhibits protein synthesis; premature chain termination
Zeocin
Shbla
HEK293, CHO, HeLa, NIH3T3, COS-1, Jurkat T cells
Complexes with DNA; causes strand scissions
The promoters of mammalian expression vectors also have different applicable objects. The most commonly used promoters are listed below:
Promoter
Primarily used for
RNA Transcript
Description
CMV
General expression
mRNA
Strong mammalian expression promoter from the human cytomegalovirus
EF1a
General expression
mRNA
Strong mammalian expression from human elongation factor 1 alpha
SV40
General expression
mRNA
Mammalian expression promoter from the simian vacuolating virus 40
PGK1 (human or mouse)
General expression
mRNA
Mammalian promoter from the phosphoglycerate kinase gene
Ubc
General expression
mRNA
Mammalian promoter from the human ubiquitin C gene
Human beta actin
General expression
mRNA
Mammalian promoter from the beta actin gene
CAG
General expression
mRNA
Strong hybrid mammalian promoter
TRE
General expression
mRNA
Tetracycline response element promoter
UAS
General expression
mRNA
Drosophila promoter containing Gal4 binding sites
CaMKIIa
Gene expression for optogenetics
mRNA
Ca2+/calmodulin-dependent protein kinase II promoter