1Department of Biophysical Chemistry, Max Planck Institute of Biophysics, 2Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt
Here we present an electrophysiological method based on solid supported membranes with focus on its applications for the characterization of electrogenic membrane transporters.
Published May 11, 2013. Keywords: Biochemistry, Biophysics, Molecular Biology, Cellular Biology, Physiology, Proteins, Membrane Lipids, Membrane Transport Proteins, Kinetics, Electrophysiology, solid supported membrane, SSM, membrane transporter, lactose permease, lacY, capacitive coupling, solution exchange, model membrane, membrane protein, transporter, kinetics, transport mechanism
1Molecular and Cell Biology, University of Connecticut, 2University of Connecticut
The ECIS/Taxis system is an automated, real-time assay that measures cellular chemotaxis. In this assay, cells move beneath a layer of agarose to arrive at a target electrode. Cellular movement is measured by the onset of resistance to AC current 0.
Published April 1, 2012. Keywords: Cellular Biology, Electric Cell- substrate Impedance Sensing, ECIS, ECIS/Taxis, Chemotaxis
1LSA Biophysics, University of Michigan, 2LSA Biophysics, Department of Physics, University of Michigan
We illustrate the use of a constant force axial optical tweezers to explore the mechanical properties of short DNA molecules. By stretching DNA axially, we minimize steric hindrances and artifacts arising in conventional lateral manipulation, allowing us to study DNA molecules as short as ~100 nm.
Published October 13, 2011. Keywords: Bioengineering, Genetics, DNA stretching, DNA, Axial Optical Tweezers, Single-Molecule Biophysics, Biophysics
1Institute of Chemistry, Technical University of Berlin, 2The Vollum Institute, Oregon Health & Science University
We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies.
Published February 19, 2013. Keywords: Biochemistry, Chemistry, Biophysics, Bioengineering, Physiology, Molecular Biology, electrochemical processes, physical chemistry, spectrophotometry (application), spectroscopic chemical analysis (application), life sciences, temperature effects (biological, animal and plant), Life Sciences (General), Na+, K+-ATPase, H+, K+-ATPase, Cation Uptake, P-type ATPases, Atomic Absorption Spectrophotometry (AAS), Two-Electrode Voltage-Clamp, Xenopus Oocytes, Rb+ Flux, Transversely Heated Graphite Atomizer (THGA) Furnace, electrophysiology, animal model
1Program in Biophysics, Harvard University, 2Division of Health Sciences and Technology, Harvard-MIT, 3Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School
The complete construction of a custom, real-time confocal scanning imaging system is described. This system, which can be readily used for video-rate microscopy and microendoscopy, allows for an array of imaging geometries and applications not accessible using standard commercial confocal systems, at a fraction of the cost.
Published October 20, 2011. Keywords: Bioengineering, Microscopy, confocal microscopy, microendoscopy, video-rate, fluorescence, scanning, in vivo imaging
1Department of Chemistry, University of the Pacific
The determination of the gas-phase acidities of cysteine-containing oligopeptides is described. The experiments are performed using a triple quadrupole mass spectrometer. The relative acidities of the peptides are measured using collision-induced dissociation experiments, and the quantitative acidities are determined using the extended Cooks kinetic method.
Published June 24, 2013. Keywords: Chemistry, Biochemistry, Molecular Biology, Oligopeptide, gas-phase acidity, kinetic method, collision-induced dissociation, triple-quadrupole mass spectrometry, oligopeptides, peptides, mass spectrometry, MS
1Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, 2Division of Cardiology, Sapienza University
Here we describe the isolation of adult mouse cardiomyoctyes using a Langendorff perfusion system. The resulting cells are Ca2+-tolerant, electrically quiescent and can be cultured and transfected with adeno- or lentiviruses to manipulate gene expression. Their functionality can also be analyzed using the MMSYS system and patch clamp techniques.
Published September 24, 2013. Keywords: Cellular Biology, Medicine, Cardiology, Cellular Biology, Anatomy, Physiology, Mice, Ion Channels, Primary Cell Culture, Cardiac Electrophysiology, adult mouse cardiomyocytes, cell isolation, IonOptix, Cell Culture, adenoviral transfection, patch clamp, fluorescent nanosensor
1Department of Physiology and Biophysics, Boston University School of Medicine, 2Boston University Photonics Center
With its small transparent body, well-documented neuroanatomy and a host of amenable genetic techniques and reagents, C. elegans makes an ideal model organism for in vivo neuronal imaging using relatively simple, low-cost techniques. Here we describe single neuron imaging within intact adult animals using genetically encoded fluorescent calcium indicators.
Published April 10, 2013. Keywords: Developmental Biology, Physiology, Biophysics, Neurobiology, Cellular Biology, Molecular Biology, Anatomy, Developmental Biology, Biomedical Engineering, Medicine, Caenorhabditis elegans, C. elegans, Microscopy, Fluorescence, Neurosciences, calcium imaging, genetically encoded calcium indicators, cameleon, GCaMP, neuronal activity, time-lapse imaging, laser ablation, optical neurophysiology, neurophysiology, neurons, animal model
1Institute of Biophysics, National Research Council of Italy, 2Dipartimento di Sistemi e Informatica, Università di Firenze, 3Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia
We measured the tension release in an axon that was partially lesioned with a laser dissector by simultaneous force spectroscopy measurement performed on an optically-trapped probe adhered to the membrane of the axon. The developed experimental protocol evaluates the axon adhesion to the culture substrate.
Published May 27, 2013. Keywords: Bioengineering, Biophysics, Neuroscience, Cellular Biology, Biomedical Engineering, Engineering (General), Life Sciences (General), Physics (General), Axon, tension release, Laser dissector, optical tweezers, force spectroscopy, neurons, neurites, cytoskeleton, adhesion, cell culture, microscopy
1Department of Physics, Worcester Polytechnic Institute, 2Department of Chemical Engineering, Worcester Polytechnic Institute
This paper demonstrates a protocol to characterize the mechanical properties of living cells by means of microindentation using an Atomic Force Microscope (AFM).
Published June 27, 2013. Keywords: Biophysics, Bioengineering, Cellular Biology, Molecular Biology, Physics, Chemical Engineering, Biomechanics, bioengineering (general), AFM, cell stiffness, microindentation, force spectroscopy, atomic force microscopy, microscopy