TABLE 3.

Time to detection in MB and MP bottles inoculated with M. tuberculosis saline dilutions after treatment of samples with NALC-NaOH

Bacillary load in starting solution	No. of CFU/mla	No. of CFU/bottle	Time to detection (days) for:
			MB bottles					MB bottlesb
			Bottle 1	Bottle 2	Bottle 3	Bottle 4	Avg	Bottle 1	Bottle 2	Bottle 3	Bottle 4
100	0.3	1.5	31.5	36.5	30.2	34.2	33.1	NGc	NG	NG	NG
200	0.15	0.75	NG	35.3	44.3	31.0	36.8d	NG	NG	NG	NG
400	0.03	0.15	NG	NG	NG	NG		NG	NG	NG	NG
800	0.015	0.075	NG	NG	NG	NG		NG	NG	NG	NG

^aThe numbers of CFU were double-checked on Middlebrook 7H11 agar plates.

^bAll specimens were processed and pretreated with NALC-NaOH, as described in the text.

^cNG, no growth after 60 days.

^dOne of four bottles showed no growth; the value given is the average of three bottles.