High speed centrifugal separator for rapid on-line sample clarification in biotechnology

Sample clarification is a common operation in biochemical analytical methods for removing interfering or unwanted particulates from an analyte sample. Filtration provides one option for removal of particulates. However, in many cases the loss of soluble protein due to filter adsorption is unacceptable and an alternative must be sought. In this paper a microcentrifuge designed to automatically sample, spin, deliver supernatant to an analyser and wash out solids from the bowl is described. The performance of the system is assessed in terms of its clarification efficiency and the time required to achieve satisfactory clarification. Additionally, the effects of different protein precipitating agents on yeast homogenate samples separated using the microcentrifuge are studied where the system is used to deliver supernatant to a flow injection analyser. The paper demonstrates that the microcentrifuge may be used to separate rapidly such samples on a time scale between 10-60 s depending upon the type and size of sample and be successfully used as a component of an at-line monitoring system.