Use of Sequential Injection technique and robotics for the automation of rhFXIII fluorometric activity assay. case...

This paper evaluates the feasibility of two systems-the Sequential Injection (SI) analyzer and the Zymark Benchmate (ZB) robot-for the automation of a recombinant human Factor Thirteen (rhFXIII) fluorometric assay. The goal was to develop a routine analytical procedure suitable for the quality control lab environment. The experimental efforts focused on monitoring of the product formation for the condensation reaction between monodansyl cadaverin and dimethyl casein. The acquired kinetic data demonstrated that both systems are capable of automating the solution handling operations associated with the assay. Using a method developed with the SI system, samples containing 0-410 mug/ml of rhFXIII were analyzed, with a throughput of one sample per 8 min, and a total solution consumption of 0.8 ml. The relative standard deviation for 10 injections of 100 mug/ml rhFXIII sample was 0.91%. With the ZB robot, samples containing 0-2500 mug/ml of rhFXIII were analyzed, and the linear response was obtained for a concentration range between 0 and 1250 mug/ml of rhFXIII. The method had a sample throughput of one sample per 11 min and a total solution consumption of 6.3 ml for each analysis. Due to its commercial availability, the ZB system was preferred over the experimental SI system for the purpose of routine automated analysis of a large number of samples in the quality control lab environment.