TABLE 4.

Transformation frequencies as determined by coculture assay

Donor strain	Transformation frequencya
HH508 (plasmid control) + MS11-Spc	2.32 × 10−5
HH508 + MS11-Spc + DNase	<1.06 × 10−7b
HH507 (traG mutant) + MS11-Spc	<4.70 × 10−7b
HH507 + MS11-Spc + DNase	<3.62 × 10−7b
HH508	<4.50 × 10−8b
HH507	<1.04 × 10−7b
MS11-Spc	<1.62 × 10−8b

^aCalculated as Cm^r Sp^r CFU/total CFU for HH508, HH507, and MS11-Spc and as Cm^r Sp^r CFU/total recipient (Sp^r) CFU for mixed cultures. Frequencies are expressed as geometric means from three different experiments. 

^bNo transformants were obtained. Values expressed are limits of detection.