Quantitative Live Single-cell Mass Spectrometry with Spatial Evaluation by Three-Dimensional Holographic and Tomographic Laser Microscopy.

The locations and volumes of the contents of a single HepG2 cell were visualized under three-dimensional (3D) holographic and tomographic (HT) laser microscopy, colored by refractive index, not staining. After trapping the specific area of a target cell in a nanospray tip, quantification was performed by live single-cell mass spectrometry. Comparison of the HepG2 cells' before and after 3D-HT images allowed the inference of the precise volume and original location of the trapped cell contents.

Direct Lipido-Metabolomics of Single Floating Cells for Analysis of Circulating Tumor Cells by Live Single-cell Mass Spectrometry.

Direct trapping of a single floating cell, i.e. a white blood cell from a drop of blood, within a nanospray tip was followed by super-sonication after the addition of ionization solvent.

Cell-surface receptor control that depends on the size of a synthetic equilateral-triangular RNA-protein complex.

A human cell surface displays many complex-structured receptors for receiving extracellular signals to regulate cellular functions. The use of precisely regulated signal-controls of the receptors could have possibilities beyond the current synthetic biology research that begins with the transfection of exogenous molecules to rewire intracellular circuits. However, by using a current ligand-receptor technique, the configuration of the artificially assembled cell surface molecules has been undefined because the assemblage is an unsystematic molecular clustering.

Synthetic translational regulation by an L7Ae-kink-turn RNP switch.

The regulation of cell signaling pathways and the reconstruction of genetic circuits are important aspects of bioengineering research. Both of these goals require molecular devices to transmit information from an input biomacromolecule to the desired outputs. Here, we show that an RNA-protein (RNP)-containing L7Ae-kink-turn interaction can be used to construct translational regulators under control of an input protein that regulates the expression of desired output proteins.