Antibodies for immunolabeling by light and electron microscopy : not for the faint hearted

Reliable antibodies represent crucial tools in the arsenal of the cell biologist and using them to localize antigens for immunocytochemistry is one of their most important applications. However, antibody-antigen interactions are much more complex and unpredictable than suggested by the old 'lock and key' analogy, and the goal of trying to prove that an antibody is specific is far more difficult than is generally appreciated. Here, we discuss the problems associated with the very complicated issue of trying to establish that an antibody (and the results obtained with it) is specific for the immunolabeling approaches used in light or electron microscopy. We discuss the increasing awareness that significant numbers of commercial antibodies are often not up to the quality required. We provide guidelines for choosing and testing antibodies in immuno-EM. Finally, we describe how quantitative EM methods can be used to identify reproducible patterns of antibody labeling and also extract specific labeling distributions.Peer reviewe

Rhythmic Micro-Gestures: Discreet Interaction On-the-Go

We present rhythmic micro-gestures, micro-movements of the hand that are repeated in time with a rhythm. We present a user study that investigated how well users can perform rhythmic micro-gestures and if they can use them eyes-free with non-visual feedback. We found that users could successfully use our interaction technique (97% success rate across all gestures) with short interaction times, rating them as low difficulty as well. Simple audio cues that only convey the rhythm outperformed animations showing the hand movements, supporting rhythmic micro-gestures as an eyes-free input technique

A Marvelous Man

An account of Geoff Davis’s enormous contribution to African Studies

Preparation of a Key Intermediate for the Angiotensin II Antagonist Losartan via Vilsmeier Chloroformylation

A novel preparation of 2-butyl-5-chloro-3H-imidazole-4-carbaldehyde, a key intermediate for the synthesis of the angiotensin II antagonist Losartan potassium, via Vilsmeier chloroformylation of imidazolinone is described

Characterisation of solution-processable organic light emitting diodes

A range of new materials for organic light emitting diodes (OLEDs) synthesised in the Department of Chemistry at Durham University have been characterised and electroluminescent devices containing these materials have been optimised. High triplet oxadiazole based electron transport materials were tested in devices blended with the host material poly(9-vinylcarbazole) (PVK). The materials exhibit comparable performance to standard OXD-7 in electrophosphorescent devices, while emission from exciplex devices indicate the new materials have higher LUMO energies than OXD-7. Single layer devices containing new sky-blue iridium(III) emitters were optimised. The improved solubility of these emitters over FIrpic, the standard sky-blue emitter, resulted in improved device efficiency and brightness due to reduced aggregation, concentration quenching and self absorption in film, and higher radiative yield. Derivatives of these new emitters, with emission shifted towards a deeper blue, were characterised. Increased trapping by the PVK host led to a reduction in the device efficiency for these materials. Two series of iridium(III) emitters with emission tuned from green to red by systematically substituted electron withdrawing or donating groups were characterised. Photophysical properties of these emitters, including the solvatochromic shift of photoluminescence spectra, correlate with theoretical values of the molecular dipole moment, thus linking changes in chemical structure with device performance. Finally, white electroluminescence was demonstrated from single copolymers exhibiting broadened blue-green intramolecular charge transfer emission due to the interaction of fluorene (F) and dibenzothiophene-S,S-dioxide (S) units. Single layer and multilayer devices were optimised, and white emission with good spectral coverage and CIE coordinates of (0.35, 0.39) was achieved with the F/S copolymer. The emission colour varies significantly with emissive layer thickness and applied voltage. Addition of a thermally evaporated electron transport layer resulted in improvement in both device efficiency and colour stability

MOM19, an import receptor for mitochondrial precursor proteins

We have identified a 19 kd protein of the mitochondrial outer membrane (MOM19). Monospecific IgG and Fab fragments directed against MOM19 inhibit import of precursor proteins destined for the various mitochondrial subcompartments, including porin, cytochrome c1, Fe/S protein, F0 ATPase subunit 9, and F1 ATPase subunit β. Inhibition occurs at the level of high affinity binding of precursors to mitochondria. Consistent with previous functional studies that suggested the existence of distinct import sites for ADP/ATP carrier and cytochrome c, we find that import of those precursors is not inhibited. We conclude that MOM19 is identical to, or closely associated with, a specific mitochondrial import receptor