LacZ expression assay

After overnight incubation, remove the homogenates and RA-containing F9 assay medium from the cells, wash twice with PBS, and develop the reporter cells for detection of lacZ expression as described in Subheading 3.2., steps 14-19... 

After 4 d of growth at 30°C, the colonies that grow under histidine selection are assayed for lacZ expression using the -galactosidase filter assay described in Subheading 3.3.2. This protocol uses filter-paper circles that are 145 mm in diameter and these are incubated on 9 mL of Z-buffer containing X-gal dispensed in the lids of 150-mm culture dishes. 

Another method is explored with gene expression-based biosensors [19] for Cd measurement. A Cd-responsive promoter from E. coli is fused to a promoterless lacZ gene and monitored with an electrochemical assay of /J-galac-tosidase activity. The expected detection limit is about 0.1 mg L 1 with a response of a few minutes. As for stripping voltammetry, no real tests have been carried out for wastewater. However, biosensors can be considered as a promising technique for wastewater monitoring. 

Figure 21.3 Histochemical analysis of / -galactosidase gene expression in liver. Ten pa of pCMV-LacZ plasmid DNA were injected into a mouse via the tail vein using the hydrodynamics-based procedure, / -galactosidase gene expression was assayed eight hours post injection. HV, hepatic vein HA, hepatic artery PV, portal vein (50x). (see Color Plate 15)...

This 35-kDa protein was confirmed as the vCKBP by pierforming the same assays with two recombinant Ws, W RPVA35 and W Lister A35 from which the fully functional gene had been inactivated by insertion of the LacZ gene. Neither of these viruses produced a secreted protein that bound to I-chemokine. Furthermore, when the W Lister 35-kDa ORF was expressed with a G-terminal 6xHis-tag in the baculovirus system, or as an Fc fusion protein from stably transfected mammalian cells, binding of the recombinant products to... 

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