Liquid-crystalline polymalonates with a definite distance between the contact points of two neighbouring side groups were synthesized. The mesogenic group is azobenzene with a terminal nitro-substituent acting as an indicator for dielectric measurements. The influence of the number of methylene groups in the main chain on the polymorphism and the dielectric behaviour has been investigated. Generally, the thermal stability of the mesophases decreases when the main chain spacer becomes longer. The relaxation frequency for the reorientation of the mesogenic side group around the short axis increases with increasing number of methylene groups in the main chain in both, the isotropic and liquid-crystalline phases.CCC 0025-1 16)3/93/$05.00

Currently, one of the most important techniques in proteome analysis is two-dimensional electrophoresis that is widely used for separation of thousands of different protein spots. Nevertheless, characterization of special aspects in protein patterns, e.g., separation of protein isoforms generated by post-translational modifications, requires individual detection methods, e.g., immunoblotting. Blotting of proteins after fractionation in immobilized pH gradients has always caused some problems. In this paper we present an optimized protocol for immunoblotting after isoelectric focusing using immobilized pH gradient (IPG) strips cast on Net-Fix as an internal support that is permeable to electric current. The focusing procedure can be carried out in commonly used IPG systems, e.g., the IPGphor by Amersham Biosciences, where electrically assisted rehydration can be performed. This may be of interest for many laboratories, because the same system as used for the first dimension of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is involved. As an example, we describe separation and detection of up to seven isoforms of recombinant erythropoietin beta using semidry blotting of IPG strips and visualization by chemiluminescence detection.

SUMMARY: To investigate the influence of a systematic variation of the length of main chain and side group spacers on the thermal phase behaviour four homologous series of liquid crystalline side group polyesters with 4-(phenylazo)azobenzene moieties as mesogenic side groups have been prepared and characterized. The polyesters exhibit smectic and/or nematic phases. The mesomorphic properties were studied by using optical polarizing microscopy, differential scanning calorimetry (DSC) and X-ray diffraction. Packing models of the low ordered smectic phases have been derived from X-ray data.

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