SOME COMMONLY OVERLOOKED PROPERTIES OF CALCIUM BUFFER SYSTEMS - A SIMPLE METHOD FOR DETECTING AND CORRECTING STOICHIOMETRIC IMBALANCE IN CAEGTA STOCK SOLUTIONS

When the two-solution approach is used to make CaEGTA buffers, the mos t critical requirement is that the CaEGTA stock solution contain equim olar quantities of calcium and chelator. The impact on [Ca2+] of error s in the molar ratio is magnified at high buffer ratios, so stoichiome tric imbalance is most readily detected there. In this paper we examin e some of the properties of calcium buffer systems that illustrate the se principles, and describe a simple and sensitive method for detectin g and correcting stoichiometric imbalance in the CaEGTA stock solution . The method derives its high sensitivity from the fact that the CaEGT A stock solution itself represents a calcium buffer system with a very high buffer ratio.