TABLE 1.

Parameters for the environmental limit of detection in soil

Detection methoda	Amt of soil	Sample concn	Pretreatment/extraction method (company)	Time (h)	Difficulty level	Extraction vol (μl)	Vol added to reaction (μl)	Total vol (μl)	Limit of detection (CFU/g soil)	Soil type/location	Reference
PCR-ELISA	100 g	1-100 CFU/100 g	Easy DNA kit (Invitrogen)	2.5	2	100	60	60	0.1	Nonsuspicious sites	10
	100 g	1-100 CFU/100 g	Easy DNA kit (Invitrogen)	2.5	2	100	60	60	1.0	Contaminated sites with organic compounds and tanning agents	10
Nested PCR + 2× cultivation in TSB	1 g	0, 1, 10, 102, 103 CFU/g	FastDNA SPIN kit	36.0	4			25	1.0	Garden soil with 3% peat	24
Nested PCR + cultivation in TSB	1 g	0, 1, 10, 102, 103 CFU/g	FastDNA SPIN kit	18	3			25	1.0 × 102	Garden soil with 3% peat	24
Nested PCR	1 g	0, 1, 10, 102, 103 CFU/g	FastDNA SPIN kit	2	2			25	1.0 × 103	Garden soil with 3% peat	24
	100 mg	106 CFU/100 mg	Three freeze-thaw cycles/glass beads and glass milk	3.5	5	30	5	25	1.0 × 105	Litter, meadow, cultivated, swamp, and lawn	63
PCR	1 g	2.5 × 103-2.5 × 107 CFU/g	Hot detergent/bead mill homogenization	1	3	100	10	100	2.5 × 103	Anthony fine sandy loam from New Mexico agriculture fields	44
Immunofluorescence	1 g	103-107 CFU/g	Aqueous polymer two-phase system	0.75	2	100	20	40	5.6 × 103	Sand	2
	1 g	103-107 CFU/g	Aqueous polymer two-phase system	0.75	2	100	20	40	1.4 × 104	Garden	2
Real-time PCR	0.1 g	103-107CFU/g	Heat treatment with 1.22 g/ml sucrose-0.5% Triton X-100	0.75	3	1,000	5	25	1.0 × 104	National Institute of Health—Korea	60
Multiplex PCR	0.1 g	103-107 CFU/g	Heat treatment with 1.22 g/ml sucrose-0.5% Triton X-100	0.75	3	1,000	1	25	1.0 × 105	National Institute of Health—Korea	60
	0.1 g	103-107 CFU/g	Heat treatment with sterilized water and 10% Triton X-100-PBS	1.5	3	1,000	1	25	1.0 × 108	National Institute of Health—Korea	60
IM-ECL	1 mg	0-106 CFU/assay	IM separation performed twice and resuspended in PBS	1.5	3				1.0 × 105	Moist, dark brown to black soil and dry, light yellowish sandy soil from diverse military and agriculture fields	18
	1 mg	0-106 CFU/assay	IM separation performed twice and resuspended in PBS	1.5	3				1.0 × 106	Moist, dark brown to black soil and dry, light yellowish sandy soil from diverse military and agriculture fields	18
	1 mg	0-106 CFU/assay	IM separation performed twice and resuspended in PBS	1.5	3				1.0 × 107	Moist, dark brown to black soil and dry, light yellowish sandy soil from diverse military and agriculture fields	18
Biosensor assay	1 mg/ml powder in PBS	3.2 × 103-3.2 × 105 CFU/ml	Washing with 1 ml PBST	0.25	1	30	5	25	3.2 × 108	Talc-based powder, cornstarch, confectioners' sugar, baking soda, and Bacillus thuringiensis-based pesticide	69

^aTSB, Trypticase soy broth.