No abstract

Imaging of live cells in a region of interest is essential to life science research. Unlike the traditional way that mounts CO2 incubator onto a bulky microscope for observation, here we propose a wireless microscope (termed w-SCOPE) that is based on the “microscope-in-incubator” concept and can be easily housed into a standard CO2 incubator for prolonged on-site observation of the cells. The w-SCOPE is capable of tunable magnification, remote control and wireless image transmission. At the same time, it is compact, measuring only ~10 cm in each dimension, and cost-effective. With the enhancement of compressive sensing computation, the acquired images can achieve a wide field of view (FOV) of ~113 mm2 as well as a cellular resolution of ~3 μm, which enables various forms of follow-up image-based cell analysis. We performed 12 hours time-lapse study on paclitaxel-treated MCF-7 and HEK293T cell lines using w-SCOPE. The analytic results, such as the calculated viability and therapeutic window, from our device were validated by standard cell detection assays and imaging-based cytometer. In addition to those end-point detection methods, w-SCOPE further uncovered the time course of the cell’s response to the drug treatment over the whole period of drug exposure.

Cellular environments are inherently dynamic and generally involve complex, temporally varying signals. Reconstruction of these environments with high spatial and temporal fidelity and simultaneous imaging of intracellular dynamics in live cells remains a major challenge. In this paper, a microfluidic chemical function generator (μCFG) was proposed for probing cell dynamic signaling with high temporal resolution. By combining a hydrodynamic gating module with a chaotic advection mixing module, the μCFG was able to generate a variety of chemical waveforms, such as digital pulsatile chemical waveforms with a frequency higher than 10 Hz and analog chemical waveforms with a frequency higher than 0.2 Hz. The shape, frequency, amplitude, and duty cycle of the waveforms could be also conveniently modulated. To demonstrate the capability of μCFG of probing fast biological processes and elucidate signal transduction pathways in complex signaling networks, a variety of temporal responses of Ca signaling to ATP-induced activation of the PY receptor, a prototypical G-protein coupled receptor (GPCR), were investigated in live cells by precisely and dynamically controlling their microenvironment.