Filtration has broad applications in academic and industrial research as well as in product development. In general, filter-nutsch or filter-pressure approaches are applied. Recently, an analytical photo-centrifugal set up was introduced as a new laboratory technique to characterize membranes and filterability of samples (suspensions, protein solutions, extracts, etc.).

Analytical centrifugal filtration (ACF) is based on continuous in-situ measurement of spatial resolved light transmission through a centrifugal filtration cell monitoring the volume decrease of the sample (top) or the filtrate increase (bottom) by STEP-Technology®). Centrifugal acceleration for dispersion separation can be simply set by programming rotor revolutions from 200 – 5000 rpm. Up to 12 samples (0,2 ml -1 ml) can be analyzed simultaneously. Different procedures can be applied to characterize membrane resistance and filterability of various sample types (diluted or concentrated macromolecule solutions or suspensions).

In this paper the basic measuring technique of ACF, the newly designed centrifugal filtration cells are described and corresponding quantitative analysis discussed...