TABLE 3.

Amount of DNA extracted from different soils after lysis treatments according to protocols 1 to 5^a

Soil no. (origin)b	Amt of DNA (μg/g [dry wt] of soil) ± SD extracted after lysis protocol:c
	1	2	3	4a	4b	5a	5b
1. (Australia)	17 ± 2	52 ± 2	32 ± 5	16 ± 3	33 ± 2	59 ± 1	27 ± 0
2. (Peyrat)	29 ± 2	58 ± 1	40 ± 2	29 ± 2	18 ± 3	56 ± 1	15 ± 1
3. (Côte St André)	36 ± 7	60 ± 6	148 ± 10	94 ± 7	38 ± 6	73 ± 5	47 ± 6
4. (Chazay)	9	16	NDd	32	15	15	70
6. (Dombes)	4 ± 2	26 ± 3	43 ± 1	61 ± 1	66 ± 1	160 ± 7	102 ± 5

^aQuantification was performed by phosphorimaging after dot blot hybridization with the universal probe FGPS431 (Table 2). 

^bFor soils 1, 2, 3, and 6, n = 3; for soil 4, n = 1. 

^cProtocols: 1, no treatment; 2, dry soil grinding; 3, dry soil grinding plus Ultraturrax homogenization; 4a, dry soil grinding, homogenization, and microtip sonication; 4b, dry soil grinding, homogenization, and Cup Horn sonication; 5a, dry soil grinding, homogenization, microtip sonication, and chemical and enzymatic lysis; 5b, dry soil grinding, homogenization, Cup Horn sonication, and chemical and enzymatic lysis. See also Fig. 1. 

^dND, not determined.