TABLE 1.

Specific infectivities of L1⁺ and L1⁻ virions

Expt no. and agent	Yield		Particle/ PFU ratio
	No. of particles	PFU
1
vL1Ri with IPTG	8.0 × 1010	1.3 × 109	62
vL1Ri without IPTG	13.3 × 1010	3.3 × 107	4,000
2
vL1Ri with IPTG	8.3 × 1010	1.2 × 109	69
vL1Ri without IPTG	14.0 × 1010	2.5 × 107	5,600