78
2- aminoethanesulfonic acid (TES) (CAMHBT, Sensititre®,
Thermo Scientific) [ 17 , 18 ].
●● Transparent flat bottom microtiter plates with up to 96 wells
(e.g., Corning® Costar®, Sigma-Aldrich, product No.
CLS3596).
●● Densitometer to determine the starting concentration of bac-
terial suspensions via optical density measurements at 600 nm
(OD 600 ).3 Methods
Subheading 3.1 refers to a general guideline for preparation of
pure bacterial strain cultures [ 19 ], whereas Subheadings 3.2 and
3.3 refer to examples of preparation procedures for cultures from
urine [ 17 ] and blood [ 18 ] samples, respectively. The suggested
procedures can be modified and further optimized depending on
the sample source and the bacterial strains. During sample prepara-
tion, biological waste management guidelines should be followed.Fig. 2 Schematic showing the oCelloScope optical scanning technology applied to a microwell containing a
bacterial suspension. The optical axis of the miniaturized imaging system is tilted 6.25° relative to the horizon-
tal plane of the stage to allow scanning of volumes. Images are acquired to form an image Z-stack. When all
the bacteria are sedimented in a microwell, they are all in focus in the best-focus image
Chiara Canali et al.