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Single-Cell Biophysics: Measurement, Modulation, and Modeling
Poster Abstracts
147
98-POS
Board 49
Differences in Growth Statistics in Different Schemes of Long-Term Single-Cell
Measurements
Shunpei Yamauchi
, Hidenori Nakaoka, Yuichi Wakamoto.
n/a, Meguro City, Tokyo, Japan.
When cells with the same genotype are in the same environment, phenotypes such as cell size,
growth rate, and expression of genes are heterogeneous from cell to cell. Recently, techniques of
microfluidics have advanced greatly, enabling us to easily detect the heterogeneity and
stochasticity of single cell dynamics.
In this study, we compared the growth statistics in two different microfluidics devices for long-
term single-cell measurement. One is called dynamics cytometer (DC), in which each channel
can harbor about 50
E.coli
cells by constantly flushing out the cells at the both ends of channels.
In DC, which cell lineages remain in growth channels becomes non-deterministic. The other
device is Modified Mother Machine (MMM), which is similar to Mother Machine but has wider
channels. Cells at the bottom of channels push out other cells and are more likely to stay in
channels for a long time.
The growth statistics are expected to depend not only on micro-environments around cells
including pressure from narrow channels, efficiency of exchanging medium and so on, but also
on the selection effect within a small population determined by cellular growth heterogeneity and
the geometries of channels. We calculated the age-dependent division rates and estimated the
inherent growth rates and the relative selection effects with respect to the expected dynamics of
infinite population. The results show that the growth rate in DC was greater than that in MMM,
and the selection effect in DC was also greater than that in MMM. The difference of the growth
rates suggests that DC allows cells to grow faster than MMM for the same medium and
temperature. The result on the selection effect implies that the geometries of growth channels
matters to growth statistics in different types of microfluidic devices.