Recombinant cell lines

Garrison, P.M., Tullis, K., and Aarts J.M.M.J.G. et al. (1996). Species specific recombinant cell lines as bioassay systems for the detection of dioxin-like chemicals. Fundamental and Applied Toxicology 30, 194-203. 

Racher, A. J., and Griffiths, J. B., Investigation of Parameters Affecting a Fixed Bed Bioreactor Process for Recombinant Cell Lines, Cytotechnol., 13 125... 

An additional screening test for TCDD-like (aryl hydrocarbon receptor, AhR, active) chemicals has been developed (Garrison et al. 1996) and is available commercially (Anonymous 1997). Dubbed the CALUX (for chemically activated luciferase gene expression) system, the assay is based on recombinant cell lines into which researchers have inserted a firefly luciferase gene. When exposed to dioxin-like compounds, the recombinant cells luminesce. The method is sensitive to ppt levels of 2,3,7,8-TCDD equivalents in blood, serum, and milk (Anonymous 1997). Samples testing positive can be subjected to more definitive and specific analytical testing. 

Finally, it is worth emphasizing that the optimization of the selection method must precede any attempt to obtain recombinant cell lines. Performing a dose-response assay is highly recommended to assess the lowest concentration of the antibiotic that kills the wild-type cells after a given period of time. 

The most common strategies consist of developing recombinant cell lines expressing antiapoptotic genes that regulate the two main families of proteins involved in the apoptotic cascade the Bcl-2 and caspase families. 

Although it has been proven that a number of delta-selective inverse opioid ligands behave as inverse agonists in constitutively active recombinant cell lines, the physiological and therapeutic relevance of the inverse delta opioid agonists is still not completely understood. 

Cloning and Establishment of the Recombinant Cell Lines. Depending on the methods to be used to transfer a final gene construct or isolated gene fragments into its host, the mechanism of transfer, the copy number, and the physical state of the final construct inside the host cell should be provided. In addition, the amplification of the gene construct, if applicable, the selection of the recombinant cell clone, and the establishment of the seed should be completely described. 

Schwarz, R.D., 1993. Characterization of muscarinic agonists in recombinant cell lines. Life Sci. 52, 465-472. 

Since the mechanism for the transfer of DNA to cells can vary widely from one method to another, one suspects that very different consequences may result within the cell - events over which the experimentation has no or little control. For example, the DNA transfer method may affect the plasmid copy number average in individual clones, depending on the amount of DNA transferred to the nucleus. Electroporation may result in a lower copy number of integrated DNA than calcium phosphate-based transfection. In view of the applied selection procedures for the generation of recombinant cell lines, very different structures of integrated plasmid DNA may result... 

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