TABLE 2.

Plating efficiencies of N4 phages on various E. coli strains

Strain/plasmid	Efficiency of platinga
	N4 (WT)	N4am15	N4am23	N4am15/23
W3350supF	1.00	1.00	1.00	1.00
W3350	0.42	1.5 × 10−7	6.3 × 10−7	1.4 × 10−10
W(DE3)plysS/pET11d	0.24	3.9 × 10−8	7.1 × 10−7	1.3 × 10−10
W(DE3)plysS/pSH+	0.25	0.27	0.19	0.13
W(DE3)plysS/pSHam15	0.22	<8.6 × 10−10	0.25	<1.3 × 10−9
W(DE3)plysS/pSHam23	0.31	0.25	<1.1 × 10−8	<1.3 × 10−9
W(DE3)plysS/pSHF	0.05	0.16	0.16	0.03

^aCalculated by dividing the number of PFU obtained on a given strain by the number of PFU obtained on W3350supF. WT, wild type.