[Ca²⁺] in cytosol and SR in a Casq-null cell with BAPTA. (A) Fluorescence of X-rhod. (B) R(x,t) and (in white trace) its line average R(t). (C) Release flux (black) and [Ca²⁺]_SR(t) (red). Details of description were given in legend of Fig. 2. Note the rapid stabilization of fluorescence in the cytosol and rapid decay of release flux to very low levels, which is a consequence of the presence of BAPTA. Also note the lack of any shoulder or hump in the evolution of release flux and the drastic decay of [Ca²⁺]_SR to nearly 0, which is a consequence of the absence of Casq. ID: 082009b_s34. Average of 10 line scan images taken 48–68 min after patching is shown.