Scientific Articles - Imaging/Radiology Feed

Quantitative Analysis of Membrane Potentials

Sun, 05 Apr 2026 22:00:50 +0000

The changes that occur in electrochemical gradients across biological membranes provide us with invaluable information on physiological responses, pathophysiological processes and drug actions/toxicity. This chapter aims to provide researchers with sufficient information to carry out a quantitative assessment of mitochondrial energetics at a single-cell level thereby providing output on changes in the mitochondrial membrane potential (Δψ_m) through the utilization of potentiometric fluorescent probes (TMRM, TMRE, Rhodamine 123). As these cationic probes behave in a Nernstian fashion, changes at the plasma membrane potential (Δψ_p) need also to be accounted for in order to validate the responses obtained with Δψ_m-sensitive fluorescent probes. To this end techniques that utilize Δψ_p-sensitive anionic fluorescent probes to monitor changes in the plasma membrane potential will also be discussed. In many biological systems multiple changes occur at both a Δψ_m and Δψ_p level that often makes the interpretation of the cationic fluorescent responses much more difficult. This problem has driven the development of computational modelling techniques that utilize the redistribution properties of the cationic and anionic fluorescent probes within the cell to provide output on changes in Δψ_m and Δψ_p.

Source: http://www.springerprotocols.com/Abstract/doi/10.1007/978-1-60761-404-3_20

Measuring the Elastic Properties of Living Cells with Atomic Force Microscopy Indentation

Sun, 05 Apr 2026 22:00:50 +0000

Atomic force microscopy (AFM) is a powerful and versatile tool for probing the mechanical properties of biological samples. This chapter describes the procedures for using AFM indentation to measure the elastic moduli of living cells. We include step-by-step instructions for cantilever calibration and data acquisition using a combined AFM/optical microscope system, as well as a detailed protocol for data analysis. Our protocol is written specifically for the BioScope™ Catalyst™ AFM system (Bruker AXS Inc.); however, most of the general concepts can be readily translated to other commercial systems.

Source: http://www.springerprotocols.com/Abstract/doi/10.1007/978-1-62703-056-4_15

Correlative Optical and Scanning Probe Microscopies for Mapping Interactions at Membranes

Sun, 05 Apr 2026 22:00:49 +0000

Innovative approaches for real-time imaging on molecular-length scales are providing researchers with powerful strategies for characterizing molecular and cellular structures and dynamics. Combinatorial techniques that integrate two or more distinct imaging modalities are particularly compelling as they provide a means for overcoming the limitations of the individual modalities and, when applied simultaneously, enable the collection of rich multi-modal datasets. Almost since its inception, scanning probe microscopy has closely associated with optical microscopy. This is particularly evident in the fields of cellular and molecular biophysics where researchers are taking full advantage of these real-time, in situ, tools to acquire three-dimensional molecular-scale topographical images with nanometer resolution, while simultaneously characterizing their structure and interactions though conventional optical microscopy. The ability to apply mechanical or optical stimuli provides an additional experimental dimension that has shown tremendous promise for examining dynamic events on sub-cellular length scales. In this chapter, we describe recent efforts in developing these integrated platforms, the methodology for, and inherent challenges in, performing coupled imaging experiments, and the potential and future opportunities of these research tools for the fields of molecular and cellular biophysics with a specific emphasis on the application of these coupled approaches for the characterization of interactions occurring at membrane interfaces.

Source: http://www.springerprotocols.com/Abstract/doi/10.1007/978-1-62703-137-0_24