AN OPTICAL BIOSENSOR FOR REAL-TIME CHROMATOGRAPHY MONITORING - BREAKTHROUGH DETERMINATION

The use of an optical biosensor for immunorecognition of protein produ cts during affinity chromatography is discussed to provide rapid data describing the loading and subsequent breakthrough, followed by elutio n and fraction collection. The optical biosensor works by following in real-time the interaction of soluble ligate with an appropriate ligan d attached to the optically active surface. The initial rate of intera ction between soluble ligate and immobilized ligand has been shown to correlate well with ligate concentration. This method of analysis has also been shown to agree well with ELISA, the traditionally employed t echnique for immunoassay of protein products lacking, for example, cat alytic activity. Forward prediction, using models of the breakthrough fitted to the real-time data, has enabled the column saturation point to be determined before it has been reached, thus enabling appropriate action to ensure minimal loss of protein product while improving colu mn utilization efficiency. The biosensor, operated within a flow injec tion analysis regime, has been demonstrated to provide concentration d ata within 10 s, with a total assay turnaround of 30 s. (C) 1998 Elsev ier Science S.A. All rights reserved.