Table 3. SYBR Green I/PI assay applied to MIC test on Borrelia burgdorferi ^a.

Green/Red ratio	Drug concentrations used in MIC test (µg/ml)										MIC reported from literature (µg/ml)
	0.0	0.2	0.4	0.8	1.6	3.1	6.3	12.5	25.0	50.0
Doxycycline	8.7 (+)b	6.1 (−)c	5.9 (−)	5.9 (−)	6.0 (−)	5.9 (−)	6.0 (−)	5.8 (−)	5.8 (−)	5.7 (−)	0.06 to 2d
Amoxicillin	9.0 (+)	6.8 (−)c	6.6 (−)	6.3 (−)	6.3 (−)	6.3 (−)	6.2 (−)	6.0 (−)	6.0 (−)	5.8 (−)	0.03 to 2d
Metronidazole	8.4 (+)	9.0 (+)	8.2 (+)	7.9 (+)	7.9 (+)	8.2 (+)	8.2 (+)	8.1 (+)	6.1 (−)c	6.0 (−)	0.06 to 32e
Vancomycin	8.0 (+)	7.4 (+)	6.1 (−)c	5.7 (−)	6.1 (−)	5.9 (−)	6.2 (−)	5.9 (−)	6.1 (−)	6.1 (−)	0.25 to 2d

^a.The values in the table represent the mean Green/Red fluorescence ratios of three replicates. The results of triplicate microscope testing were correspondent.

^b.Direct microscope counting results (+: grow, −: no grow) are shown in brackets.

^c.MIC breakpoints determined by SYBR Green I/PI assay are shown in boldface.

^d.Hunfeld, K. P. and V. Brade (2006). See reference [19].

^e.Sapi, E., et al. See reference [6].