Population size matters: The cause & effect of heterogeneous β1AR expression and its influence on receptor internalization.

In cellular physiology, the impact of heterogeneous receptor expression is a topic that has recently started to receive much attention from the scientific community. However, much is still not understood about the specifics on the ori- gin of this heterogeneity nor how it affects bulk measurements of heterogeneous population. While the literature often acknowledges this heterogeneity, it falls short of offering an explanation of what practical implications this variability may have. In this paper, we examine two methods for evoking protein expression of G Protein-Coupled Receptors, transient transfection and inducible cell lines, and show that these methods have markedly different expression variabilities. While the inducible cell lines have relatively homogeneous expression profiles, the tran- sient transfected cells showed large variability to an extent that bulk measurements of transfected cells may yield misleading data. We hope that the results presented in this paper may inspire future research in the field to fully consider the effects of heterogeneous expression profiles

Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes

Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM) has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained