Faraday Discussions Blog

Super resolution microscopy breaks the diffraction limit. Professor Dr Stefan Hell is credited for the development of STED or stimulated emission depletion microscopy. In this paper arising from the Faraday Discussion on Lipids & Membrane Biophysics STED is used in combination with FCS or fluorescence correlation spectroscopy to follow the diffusion of dye labeled lipids in membrane model systems on glass and mica.

Super resolution microscopy is used to study the diffusion of labelled lipids, two labels are employed, one that localises in the liquid ordered and one that localises in the liquid disordered phase of the lipid membrane model. Through STED, and with the two new probes introduced, the rate of 2D diffusion in the membrane can be measured. As the localisation of the two probes is different, a map of the disordered and ordered domains can be generated.

by Dr Thomas Just Sørensen

Read this fascinating article which was presented as part of the Faraday Discussion on Lipids & Membrane Biophysics:

STED microscopy detects and quantifies liquid phase separation in lipid membranes using a new far-red emitting fluorescent phosphoglycerolipid analogue
Alf Honigmann, Veronika Mueller, Stefan W. Hell and Christian Eggeling
DOI: 10.1039/C2FD20107K

Read all the results and Discussion in the Lipids & Membrane Biophysics Discussion volume.

We’d love you to join us at a future meeting: more details on the Faraday Discussions events website.

We’d love you to join us for FD162: Fabrication, Structure and Reactivity of Anchored Nanoparticles which will take place in Berlin, Germany from 10-12 April 2013.

Check out the programme on the website – highlights include Gabor Somorjai (University of California at Berkeley) and Charlie Campbell (University of Washington Seattle) giving the opening and closing lectures.

Faraday Discussions are a unique and high-impact series of international conferences. Each Faraday Discussion is on a specific “hot topic”, and 24 papers are presented and discussed by world class speakers.

The 24 papers and discussion (including new research presented by any delegate) are published in the Faraday Discussions journal. The journal is SCI indexed, and the latest Impact Factor (IF) is 5.0

Attending a Faraday Discussion is a unique opportunity to discuss your work with leading researchers in important areas of physical chemistry, biophysical chemistry and chemical physics.

We hope to see you there! Register to attend by 15th March 2013.

Figure reproduced from the Introductory Lecture of FD160 (DOI: 10.1039/C2FD20128C)

If you take two glasses of water and dissolve sodium chloride in the one and sodium iodide in the other, I can tell you that in the first glass you have a deficiency of anions in the water-air interface and an accumulation of negative ions in the same interface in the latter glass. I can also tell you that if you dip a glass stirrer into one glass it will become negatively charged, where it in the other will get a positively charged. The last piece of wonder I can share is that if you use a plastic spoon instead the effects are reversed.

The examples I gave above are all examples of Hofmeister effects, where the nature of a small ion dictates specific events to occur in larger systems. The example with iodide and chloride are not the most extreme and the effects described above are small. The extreme cases include sulphate, perchlorate and hexafluorophosphate, the former is extremely hydrophilic and the two other are very lipophilic. Cations are an altogether different story all-together.

The importance of the Hofmeister effects are not to be underestimated as all biological processes and structures have to exist in ion-rich environments. Strip away the ions or introduce large quantities of an alien small ion and the processes and structures are disrupted. Killing an organism by introducing potassium is an easy experiment. Understanding the effects of chloride, bromide and sodium on every single piece of the biological machinery is much more challenging. The challenge is being met by the group of researchers who attended the 160^th Faraday Discussion on Ion Specific Hofmeister Effects. Their latest findings and a thorough introduction to the subject is published in the recent issue of Faraday Discussions.

Much, much more information and many insights can be gleaned in the themes issue of Faraday Discussion on Ion Specific Hofmeister Effects.

by Dr Thomas Just Sørensen