Measurement of incident angle dependence of swimming bacterium reflection using on-chip single-cell cultivation assay

We have developed an on-chip single-cell microcultivation assay as a means of continuously observing certain single swimming cells in order to trace their movement. The single cells were captured in microchambers fabricated on thin glass slides and having semipermeable membrane lids, in which cells can swim within the space for a long term without escaping. This assay enables the direct measurement of the reflection of certain cells against the microchamber walls depending on their incidence angles. Using this assay, the reflection was examined. We found that the ratio of reflection of cells to those of non- reverse was almost the same, though most of cells reflected when their incident angle was perpendicular to the wall.