Table 2.

Real samples measured with conventional methods and the hybridized label-free DNA biosensor.

Sample	Biochemical Test				Impedance Signal, RCT	Conventional Method
	Gramstaining	Catalase	Oxidase	Indole	(Average) (n = 3)	Chromocult Coliform Agar	Eosin Methylene Blue Agar (n = 3)
E. coli ATCC 25922	Negative Rod	Positive	Negative	Positive		Blue and purple colored “coliform”	Green metallic colored coliform
Water from factory surroundings	Negative Rod	Positive	Negative	Positive	343.62 Ω	Blue, purple, and red colored “coliform”	Green metallic colored coliform 75–80 cfu/100 ml
Water from wet market surroundings	Negative Rod	Positive	Negative	Positive	302.38 Ω	Blue and purple colored “coliform” (TMTC)	Green metallic colored coliform >80 cfu/100 ml
Water from café surroundings	Negative Rod	Positive	Negative	Positive	369.85 Ω	Blue, purple, and red colored “coliform”	Green metallic colored coliform 60–70 cfu/100 ml