Table 1.

pH of Young and Mature Vacuoles

	Condition	Age	n	pH	Error
Phagosomes containing NHS-carboxyfluorescein–labeled particles	Live E. coli	45–75 min	17	5.6	0.32
	Live L. pneumophila	3–6 h	56	7.4	0.9
	Heat-killed L. pneumophila	2–4 h	41	5.5	0.3
Vacuoles containing fluorescein dextran	L. pneumophila	16–22 h	64	5.6	0.8
	L. pneumophila + 1 μM BFA	17–20 h	22	7.3	0.8
	Macrophage vesicles	2 h	300	5.5	0.3
	Macrophage vesicles + 1 μM BFA	2 h	90	7.6	0.59