FM 4-64 (Molecular Probes) was added to a
final
concentration of 0.5 mg/mL in a 1.2% solution of molten agar/media
(CH or LB diluted 1:5 in water) and added to the well of a culture
slide and covered with a glass slide. After cooling, the slide was
removed and two air pockets were cut out of the agar leaving a 3 to
5 mm agar bridge in the center of the well.