EGTA
EGTA: translation
(= ethyleneglycol-bis(2-aminoethyl) N,N,N&’,N&’,-tetraacetic acid) )
Like EDTAa chelator of divalent cations but with a higher affinity for calcium (log Kapp 6.68 at pH 7) than magnesium (log Kapp 1.61 at pH 7). Will also bind other divalent cations. Note: the "apparent association constant", Kapp, is used because protons compete for binding and the association constant varies according to pH. Thus, EGTA has log10 Kapp for calcium of 2.7 at pH 5, 10.23 at pH 9.