Table 1.

Properties of the MerR libraries and parameters used in flow cytometric cell sorting

MerR library	Diversitya	Backgroundb	Low-fluorescence screening (sort 1)				High-fluorescence screening (sort 2)
			[HgCl2]c (M)	Anal. cellsd	% cells chosene	Cell handlingf	[CdCl2] (M)	Anal. cellsg	% cells chosen	Cell handlingf
A	1.0 × 106	6.0 × 104	1 × 10−5	2.2 × 107	8.3	Cult.	1 × 10−5	1.0 × 106	0.1	Plate
B	8.4 × 105	8.0 × 103	5 × 10−5	8.8 × 106	5.9	Cult.	1 × 10−4	2.0 × 106	0.5	Plate
C	4.0 × 106	7.5 × 104	5 × 10−5	4.3 × 106	6.0	Cult.	1 × 10−4	1.1 × 106	0.6	Plate

^aLibrary diversity was defined as the number of transformed cells obtained after electroporation.

^bNumber of colonies on the ligation control plate (ligation reaction only with insert-free vector).

^cMetal concentration used for induction of the merR library.

^dAnal. cells, number of cells analyzed from the initial library.

^ePercentage of the sorted cells collected with the flow cytometer.

^fMethod used to handle the cells after flow cytometric cell sorting: Cult., sorted cells were directly cultivated in liquid medium for the next sorting step; Plate, sorted cells were collected on filter papers that were then placed on LA plates.

^gNumber of cells analyzed after the first round of sorting.