A GENERAL-METHOD TO RECONDITION AND REUSE BIACORE SENSOR CHIPS FOULEDWITH COVALENTLY IMMOBILIZED PROTEIN PEPTIDE

Of significance in the routine use of BIAcore is the cost of the senso r chips, This is particularly evident during the phase of method devel opment of an assay where it is not unusual to expend several chips in a day in attempts to optimize immobilization conditions for a novel pe ptide or protein. In addition, it is accepted practice to discard a ch ip once its ligand binding capacity has diminished to an unacceptable level, While the high cost of sensor chips has been addressed to some degree through the recent introduction of research-grade sensor chips, we were interested in assessing the possibility of regenerating or re conditioning sensor chips in order to allow them to be reused. In part icular, we concerned ourselves with regenerating sensor chips onto whi ch peptide or protein had been immobilized. Our aim was to develop a g eneral procedure that would allow reuse of such chips but would not de crease ligand immobilization capacity or increase nonspecific ligand a dsorption properties, We present a method which employs a combination of enzymatic (Pronase E) and chemical (bromoacetic acid) treatments of used sensor chips, Regeneration requires an overnight incubation of t he sensor chip ex situ so that one can continue to perform BIAcore exp eriments, The data demonstrate that this simple two-step procedure sub stantially removes immobilized proteins such as IgG, Protein G, an HIV -1 envelope glycoprotein (gp120) and a neoglycoprotein based on bovine serum albumin, as determined by reflectance measurements and X-ray ph otoelectron spectroscopy. In addition, a high density of proteins can be immobilized onto the reconditioned surfaces, since reactive carboxy lic acids are regenerated by the procedure. (C) 1995 Academic Press, I nc.