Bipolar electrochemical sensor with perylene diimide-based cathodic luminophore for dopamine detection and imaging.

Bipolar electrochemical microscopy (BEM), which visualizes the concentration distribution of molecular species in biological systems by electrochemiluminescence (ECL), is expected to be applied to the high-spatiotemporal-resolution imaging of biomolecules, enabling the analysis of cellular functions. In the past, the molecular species that could be imaged by BEM were generally restricted to oxidized molecules due to the limitation derived from the ECL mechanism of the luminophore. Recently, the imaging of dopamine (DA), a reduced molecule, was achieved using Ru (bpy)/glutathione disulfide (GSSG) as a cathodic luminophore.

Highly Sensitive Electrochemical Endotoxin Sensor Based on Redox Cycling Using an Interdigitated Array Electrode Device.

The amebocyte lysate (LAL) reaction-based assay, the most commonly used endotoxin detection method, requires a skilled technician. In this study, to develop an easy-to-use and highly sensitive endotoxin sensor, we created an electrochemical endotoxin sensor by using an interdigitated array electrode (IDAE) device with advantages of amplifiable signals via redox cycling and portability. We added Boc-Leu-Gly-Arg--aminophenol (LGR-pAP) as an electrochemical substrate for an LAL reaction and detected -aminophenol (pAP) released from LGR-pAP as a product of an endotoxin-induced LAL reaction via an IDAE device.

Developmental assessment of human vitrified-warmed blastocysts based on oxygen consumption.

Background: In this study, we aimed to develop a model for embryo selection based on oxygen consumption following cryopreservation, the relationship between the developmental competence of blastocysts and their oxygen consumption was assessed.

Methods: Oxygen consumption of vitrified-warmed human blastocysts was measured at 0, 1.5, 3, 4.

Monitoring oxygen consumption of single mouse embryos using an integrated electrochemical microdevice.

Oxygen consumption (respiration activity) has been found to be the most remarkable criterion for determining the viability of an embryo produced in vitro. In this study, we propose an accurate, simple, and user-friendly device for measurement of the oxygen consumption of single mammalian embryos. An integrated electrode array was fabricated to determine the oxygen consumption of a single embryo, including the blastocyst stage, which has an inhomogeneous oxygen consumption rate, using a single measurement procedure.

A microfluidic dual capillary probe to collect messenger RNA from adherent cells and spheroids.

Collection of bioanalytes from single cells is still a challenging technology despite the recent progress in many integrated microfluidic devices. A microfluidic dual capillary probe was prepared from a theta (theta)-shaped glass capillary to analyze messenger RNA (mRNA) from adherent cells and spheroids. The cell lysis buffer solution was introduced from the injection aperture, and the cell-lysed solution from the aspiration aperture was collected for further mRNA analysis based on reverse transcription real-time PCR.

Measurement of gene expression from single adherent cells and spheroids collected using fast electrical lysis.

The cytosol of a single adherent cell was collected by the electrical cell lysis method with a Pt-ring capillary probe, and the cellular messenger RNA (mRNA) was analyzed at a single-cell level. The ring electrode probe was positioned 20 microm above the cultured cells that formed a monolayer on an indium-tin oxide (ITO) electrode, and an electric pulse with a magnitude of 40 V was applied for 10 micros between the probe and the ITO electrodes in an isotonic sucrose solution. Immediately after the electric pulse, less than 1 microL of the lysed solution was collected using a micro-injector followed by RNA purification and first strand cDNA synthesis.