Dual fluorescent staining of bacterial cells
The harvested bacterial cells were treated as follows: (1) 100 μL
of the harvested bacteria were centrifuged and resuspended in
100 μL of 4% PFA and incubated at 37 °C for 10 min. (2) After
centrifugation at 5000 g for 5 min, the precipitate was resuspended in 100 μL of 50 μg/mL lysozyme and incubated at 37 °C
for 20 min. (3) After centrifugation at 5000 g for 5 min, 100 μL 1%
FBS was added to the precipitate to block the bacterial cells at
room temperature for 30 min. (4) The bacterial sample was centrifuged at 5000 g for 5 min, and then 100 μL of 5 μg/mL anti-β
lactamase mAb was added. The suspension was incubated for 1 h
at 37 °C. (5) After washing twice with PBS, 100 μL of 5 μg/mL
AF488-DAM IgG was added and incubated at 37 °C for 1 h. (6) The
sample was centrifuged, resuspended in 100 μL PBS containing
1 μM SYTO 62, and then analyzed on the HSFCM