title: Dependence of transfection efficiency of calcium treated Escherichia coli cells on bacterial genotype and form of Lambda DNA.
abstract: The transfecting activity of linear lambda DNA is 100 times higher in calcium treated E. coli K12 (lambda i434) than in non-lysogenic strains: the levels of transfection are 1-2.10(7) and 1-2.10(5) infective centers per 1 mug of lambda DNA respectively. The high efficiency of lysogenic cells transfection is not due to the spontaneously liberated "helper" phage. Evidently, it is called forth by transfecting DNA-prophage recombination or/and by inhibition of nuclease activity in lysogenic cells. Both ring forms lambda DNA (supercoiled and open circles) show very low infectivity, if any, in calcinated cells.
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D002499:Centrifugation, Density Gradient; D003090:Coliphages / Q000378:metabolism*; D004270:DNA, Circular / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D005838:Genotype; D008242:Lysogeny; D013045:Species Specificity; D014170:Transformation, Genetic
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral; D002118:Calcium