TABLE 2.

LD₅₀s for different mouse strains challenged by different routes of infection^a

Route	LD50 (no. of spores)
	BALB/c	DBA/2	C3H	129X1/SVJ	C57BL/6J	A/J
s.c.	19	5	5	5	19	5
i.n.	37,000	<6,250	6,250	25,000	12,500	6,250
i.t.	870	35	24	ND	500	ND

^aMice were infected with four different doses (10 mice/dose) of B. anthracis spores by either an s.c., i.n., or i.t. inoculation, and the LD₅₀ was determined. Different mouse strains were analyzed in parallel for each infection route. For the s.c. and i.n. routes one experiment was performed with all male mice (40 mice/strain) and one experiment was performed with all female mice (40 mice/strain, except no female A/J mice were used). All female mice were used in the i.t. experiment (40 mice/strain). ND, not done.