Measuring Single-Cell Phenotypic Growth Heterogeneity Using a Microfluidic Cell Volume Sensor

Abstract

An imaging-integrated microfluidic cell volume sensor was used to evaluate the volumetric growth rate of single cells from a Saccharomyces cerevisiae population exhibiting two phenotypic expression states of the PDR5 gene. This gene grants multidrug resistance by transcribing a membrane transporter capable of pumping out cytotoxic compounds from the cell. Utilizing fluorescent markers, single cells were isolated and trapped, then their growth rates were measured in two on-chip environments: rich media and media dosed with the antibiotic cycloheximide. Approximating growth rates to first-order, we assessed the fitness of individual cells and found that those with low PDR5 expression had higher fitness in rich media whereas cells with high PDR5 expression had higher fitness in the presence of the drug. Moreover, the drug dramatically reduced the fitness of cells with low PDR5 expression but had comparatively minimal impact on the fitness of cells with high PDR5 expression. Our experiments show the utility of this imaging-integrated microfluidic cell volume sensor for high-resolution, single-cell analysis, as well as its potential application for studies that characterize and compare the fitness and morphology of individual cells from heterogeneous populations under different growth conditions.

Design and 3D modeling investigation of a microfluidic electrode array for electrical impedance measurement of single yeast cells

“…During the lifespan of budding yeast, the mother cells give birth to new buds, which are continuously growing and ultimately removed after the completion of cell division. Although the budding yeast is known to present an exponential growth, volumetric growth rate of yeast cell with a bud could be regarded as a constant via a first‐order approximation [49]. Considering that the obtained EIS signal is usually raw amplitude of response current ( I rec ), the growth of daughter cell during yeast budding process in Fig .…”

Active particles as mobile microelectrodes for selective bacteria electroporation and transport

“…It is expected that the described biological cargo carrier and targeted electroporation can be used in applications integrating single-cell analysis methods, such as polymerase chain reaction, gene sequencing, fluorescence in situ hybridization, and immunofluorescence staining, where the carrier will selectively pick up a target and transport it to a secondary chamber to be lysed for further analysis of its genomics (43), transcriptomics (44), proteomics (45), or metabolomics (46). The selective trapping and single-cell lysis system also enable investigation of cell heterogeneity (47).…”

Robustness: linking strain design to viable bioprocesses

“…Following temperature stress, the TSL1overexpressing subpopulation immediately became the predominant subpopulation. Studies using microfluidic devices showed how, in the presence of the antibiotic cycloheximide, a subpopulation expressing higher levels of PDR5, an ATP-dependent membrane transporter, exhibited a higher specific growth rate compared to a subpopulation with low PDR5 expression [42]. Another example is the diauxic shift in Lactococcus lactis and S. cerevisiae, whereupon growth in a medium with two different carbon sources allows a subpopulation to prepare for subsequent growth on a less preferable carbon source [43,44].…”