The diffusion of fluorescently labeled lipids in supported bilayers is studied using two different methods: Z-scan fluorescence correlation spectroscopy (z-scan FCS) and two-focus fluorescence correlation spectroscopy (2f-FCS). It is found that the data can be fitted consistently only when taking into account partial sticking of the labeled lipids to the supporting glass surface. A kinetic reac...

In fluorescence correlation spectroscopy (FCS) and photon counting histogram (PCH) analysis, the same experimental fluorescence intensity fluctuations are used, but each analytical method focuses on a different property of the signal. The time-dependent decay of the correlation of fluorescence fluctuations is measured in FCS yielding molecular diffusion coefficients and triplet-state parameters...

We present a new technique, polarization-modulation dual-focus fluorescence correlation spectroscopy (pmFCS), based on the recently intro-duced dual-focus fluorescence correlation spectroscopy (2fFCS) to measure the absolute value of diffusion coefficients of fluorescent molecules at pico- to nanomolar concentrations. Analogous to 2fFCS, the new technique is robust against optical saturation in...

The diffusion of charged proteins in liquid-filled nanometer-sized apertures with charged surfaces has been investigated with fluorescence correlation spectroscopy (FCS). Based on a two-dimensional (2D) multicomponent diffusion model, key parameters such as the number of molecules diffusing freely inside the nanochannel or interacting with the surfaces, together with the specific diffusion para...

Based on a confocal microscopy platform, we extended the FCS time window by three orders of magnitude to the s timescale by attaching a polystyrene microsphere. We simultaneously monitored the relaxations of multiple intermediates involved in DNA hairpin folding, thus offering a much more detailed view of the kinetics of hairpin folding experimentally.

We adapt fluorescence correlation spectroscopy (FCS) formalism to the studies of the dynamics of semiflexible polymers and derive expressions relating FCS correlation function to the longitudinal and transverse mean-square displacements of polymer segments. The obtained relations do not depend on any specific model of polymer dynamics. We use the derived expressions to measure the dynamics of a...

A new approach to immobilize zwitterionic molecules rapidly and highly efficiently on a gold surface applies aniline-based electrodeposition. The zwitterion-functionalized antifouling surface enables a decrease of the adsorption of non-specific proteins by 95% from fetal bovine serum (FBS, 10%).

Lyophilizatin of 13 cyanobacterial cultures belonging to seven genera was attempted in a variety of suspending substances. All organisms survived lyophilization when suspended in lamb serum. Some of the organisms could be successfully lyophilized in horse serum, beef serum, fetal bovine serum, or human ascites fluid. With the exception of Nostoc muscorium, none of the organisms survived lyophil...

Stochastic effects from correlated noise non-trivially modulate the kinetics of non-linear chemical reaction networks. This is especially important in systems where reactions are confined to small volumes and reactants are delivered in bursts. We characterise how the two noise sources confinement and burst modulate the relaxation kinetics of a non-linear reaction network around a non-equilibriu...

Fluorescence correlation spectroscopy (FCS) is a powerful spectroscopic technique for studying samples at dilute fluorophore concentrations down to single molecules. The standard way of data acquisition, at such low concentrations, is an asynchronous photon counting mode that generates data only when a photon is detected. A significant problem is how to efficiently convert such asynchronously r...