Preparing samples by clarification is an essential step prior to nearly all analytical techniques, such as high pressure liquid chromatography (HPLC). This filtration step to eliminate particles is crucial for maintaining the integrity of chromatography columns and for maximizing their operating life time. In addition, as the sensitivity of automated analytical instruments continues to improve, they increasingly require less volume to operate in order to maximize throughput.

Fast small-volume clarification that does not add leachables or extractables to the original sample is indispensable for achieving the best analytical results. To meet these requirements, Sartorius, a pharma and lab equipment supplier, has developed a new, easy-to- use and straightforward filtration setup. The manually operated Claristep® filtration system consisting of a station and filter units offers a novel way for clarifying your samples prior to analysis.

The Claristep® station consists of a base, a lid and an exchangeable tray for easy and accurate positioning of sample vials and Claristep® filter units. The patent- pending design features unique grooves in the station’s lid and matching guide ridges on Claristep® filter units to enable intuitively correct alignment and convenient handling of the system. The grooves automatically guide the filter unit caps into the correct positions for simultaneous and accurate cap closure.

Claristep® enables up to eight samples to be simultaneously filtered– without needing any power supply or a vacuum | pressure source. Single-use Claristep® filter units with RC membranes are designed for sample volumes of 60 μL to 600 μL. Their hold-up volume is less than 30 μL. The units have been optimized for solvents and aqueous solutions and provide maximum chemical compatibility as well as exceptionally low non-specific binding of analytes. The contact time of the samples with the filters and the caps is extremely short, ensuring optimal, contamination-free results. Filtrates are collected in any 12 × 32 mm outer diameter vials of the user’s choice based on the analytical method to be performed.