Chemical Name: O,O EBis(2-aminophenyl)ethyleneglycol-N,N,N',N'-tetraacetic acid, tetrapotassium salt, hydrate
CAS: 85233-19-8(free acid)
Appearance: White powder or crystalline powder
Purity: ≥95.0% (Titration)
MW: 628.79, C22H20K4N2O10
Storage Condition: ambient temperature
Shipping Condition: ambient temperature
BAPTA is a calcium-selective chelator developed by Dr. Tsien. It has logKCa=6.97 and logKMg=1.77. The basic chelating unit resembles that of EGTA, but the two aliphatic nitrogen atoms are replaced by aromatic nitrogen. Thus, BAPTA is not protonated at physiological pH. BAPTA possesses pKa3=5.47 and pKa4=6.36. This property indicates that the deprotonation step is not included in its calcium complexation step, and it has a higher complexation rate than EGTA because it is not affected by proton interference. BAPTA-AM is an acetoxymethyl ester derivative of BAPTA that can be easily loaded into cells using the AM method. BAPTA-AM is useful for controlling the intracellular calcium concentration.
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8. Y. Tojyo, et al., Inhibitory Effects of Loading with the Calcium-chelator 1, 2-Bis(o-aminophenoxy)ethane-N, N, N’, N’-tetraacetic acid (BAPTA) on Amylase Release and Cellular ATP Level in Rat Parotid Cells. Biochem Pharmacol. 1990;39:1775-1779.