Single-Cell Biophysics: Measurement, Modulation, and Modeling

Single-Cell Biophysics: Measurement, Modulation, and Modeling

Poster Abstracts

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.

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