BAPTA tetracesium

BAPTA tetracesium is a selective and cell-impermeant chelator for calcium. BAPTA tetracesium has high selectivity against magnesium and calcium. BAPTA tetracesium can also inhibit phospholipase C activity independently of their role as Ca 2+ chelators ^{[1] [2] [3]}.

In Vitro, BAPTA tetracesium is widely used as an intracellular buffer to investigate the effects caused by Ca2+ release from intracellular calcium stores or Ca2+ influx via Ca2+-permeable channels in the plasma membrane^[1]. BAPTA tetracesium can be introduced into cells via methods such as patch-clamp and microinjection^[1]. BAPTA tetracesium inhibits PLC activity in isolated Drosophila melanogaster photoreceptor cells with an IC₅₀ of approximately 8 mM^[2].

References:
[1]. Tsien RY, et al. New calcium indicators and buffers with high selectivity against magnesium and protons: design, synthesis, and properties of prototype structures. Biochemistry. 1980;19(11):2396-2404.
[2]. Hardie RC. Inhibition of phospholipase C activity in Drosophila photoreceptors by 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid (BAPTA) and di-bromo BAPTA. Cell Calcium. 2005 Dec;38(6):547-56.
[3]. Collatz MB, et al. Intracellular calcium chelator BAPTA protects cells against toxic calcium overload but also alters physiological calcium responses. Cell Calcium. 1997;21(6):453-459.