TABLE OF CONTENTS To cut a long story short, modern AUC is more versatile than ever, and despite its major applications in biopolymer analysis, it returned to its roots in colloid analytics. AUC is one of the most powerful techniques known to date for the characterization of very small colloids <10 nm. The power of AUC lies in the fractionation of the sample and the possibility of measuring distributions without any interactions with the stationary phase or solvent flows. as occurrs in the commonly applied chromatographic techniques nowadays. Wherever information is sought for the individual components in a mixture, AUC is one of the first techniques of choice and, especially for nanoparticles <10 nm, the only realistic choice to determine a particle size distribution in solution. Therefore, it is expected that AUC will play an important role in colloid chemistry if researchers recognize the tremendous potential of this method.
Although the very early colloid work by AUC was of most remarkable precision, [3] it cannot compare with the present possibilities, especially in the data evaluation sector. The last six decades of AUC research were mainly dedicated to biopolymers and put forward many useful methodological developments, reflected in the large pool of freely available software (for example, http://www.cauma.uthscsa.edu/software). However, the commercial hardware development could not catch up with the demand for colloid analysis. The most significant instrumental drawback for colloid analysis was the loss of the Schlieren optics in the modern XL-I instrument, which was designed to meet the needs...
