Chemical Name: O,O EBis(2-aminophenyl)ethyleneglycol-N,N,N',N'-tetraacetic acid, tetraacetoxymethyl ester
Appearance: White powder
Purity: ≥98.0% (HPLC)
MW: 764.68, C34H40N2O18
Storage Condition: -20ºC, protect from light
Shipping Condition: ambient temperature
BAPTA is a calcium-selective chelator developed by Dr. Tsien. It has logKCa
=6.97 and logKMg
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
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.
Hydrolysis of AM ester
1) R. Y. Tsien, New Calcium Indicators and
Buffers with High Selectivity against Magnesium and Protons: Design,
Synthesis, and Properties of Prototype Structures. Biochemistry. 1980;19:2396-2404.
2) R. Y. Tsien, A Non-disruptive Technique for Loading Calcium Buffers and Indicators into Cells. Nature. 1981;290:527-528.
3) J. I. Korenbrot, et al., The Use of Tetracarboxylate Fluorescent
Indicators in the Measurement and Control of Intracellular Free Calcium
Ions. Soc Gen Physiol Ser. 1986;40:347-363.
4) S. M. Harrison,
et al., The Effect of Temperature and Ionic Strength on the Apparent
Ca-affinity of EGTA and the Analogous Ca-chelators BAPTA and
Dibromo-BAPTA. Biochim Biophys Acta. 1987;925:133-143.
W. Gelfand, et al., Dissociation of Unidirectional Influx of External
Ca2+ and Release from Internal Stores in Activated Human T Lymphocytes.
Eur J Immunol. 1990;20:1237-1241.
6) J. P. Kao, et al., Active Involvement of Ca2+ in Mitotic Progression of Swiss 3T3 Fibroblasts. J Cell Biol. 1990;111:183-196.
7) M. L. Schubert, et al., Functionally Distinct Muscarinic Receptors on Gastric Somatostatin Cells. Am J Physiol. 1990;258:G982-G987.
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.