Biology subjects

De Angelis, G.

Publications and source records attributed to De Angelis, G..

3 recordsLinked to original sources

bioRxiv2025

Parameter Optimization for Iterative MINFLUX Microscopy enabled Single Particle Tracking

MINFLUX fluorescence microscopy is a recently introduced super-resolution approach for studying cellular structures and their dynamics with highest detail. Iterative MINFLUX (iMFX) performs Single Particle Tracking (SPT) at runtime. The ad hoc signal interpretation necessary to sustain the method relies on several parameters, which need to be optimized in relation to the sample under study, such as fluorescent lipid analogues in membranes, to ensure the fidelity of the measurement. We propose a parameter optimization strategy, an overview of the most important parameters, present a theoretical upper limit for trackable diffusion rates, and demonstrate iMFX-enabled SPT of fast ([<]DMSD[>] = 2.5m2/s) lateral Brownian motion of lipids in membranes.

biophysics↗

bioRxiv2024

Homogeneous large field-of-view and compact iSCAT-TIRF setup for dynamic single molecule measurements

Interferometric Scattering Microscopy (iSCAT) enables prolonged and high frame rate Single Particle Tracking (SPT) for single molecule dynamics studies. Typically, iSCAT setups employ scanning illumination schemes to achieve uniform sample illumination. However, this implementation limits the field of view (FoV) and maximum sampling rate, while increasing hardware requirements and setup size. We demonstrate the realization of a large (60{micro}m x 60{micro}m) uniformly illuminated FoV through a passive refractive optical element in the iSCAT illumination path. This scanning-free iSCAT microscopy setup is further combined with an objective based Total Internal Reflection Fluorescence Microscopy (TIRF) channel for a complementary fluorescence readout, a focus-lock system, and a tailored control platform via the open-source ImSwitch software, and has a compact footprint. As a proof-of-principle, we highlight the performance of the setup through the acquisition of iSCAT images with a uniform contrast and a [≤]10 nm localization precision throughout the whole FoV. The performance is further demonstrated through dynamic iSCAT SPT and imaging Fluorescence Correlation Spectroscopy of lipid diffusion in a model membrane system. Our iSCAT setup thus depicts an accurate and improved way of recording fast molecular dynamics in life sciences.

biophysics↗

bioRxiv2019

Different detection capabilities by mycological media for Candida isolates from mono- or dual-species cultures

ObjectivesThe aim of this study was to compare the Candida bromcresol green (BCG) medium with the chromogenic (CHROM) Brilliance Candida agar and Sabouraud dextrose agar (SDA) media in regard to their capability of detecting Candida isolates from mono-or dual-species cultures. MethodsWe prepared Candida isolates suspensions to obtain mono-species (n = 18) or dual-species (n = 153) culture plates per each medium, and three readers independently observed 513 plates at 24-h, 48-h and 72-h incubation time. We scored reading results as correct, over or under detection compared to the expected species number(s). ResultsBCG showed significantly higher correct-detection and lower under-detection rates for all Candida species when observed by at least one reader. At 24-h reading, 12 mono-species cultures had correct (or over) detections in all media, whereas 106, 60 and 78 dual-species cultures had correct (or over) detections in BCG, CHROM or SDA, respectively. ConclusionBCG provides the basis for an accurate laboratory diagnosis of Candida infections.

microbiology↗