Coulomb Sum Rule at 0.55 GeV/$c$ $\leq \vec {\vert q \vert} \leq$ 1.0 GeV/$c$

In order to test the Coulomb sum rule in nuclei, a precision measurement of inclusive electron scattering cross sections in the quasi-elastic region was performed at Jefferson Lab. Incident electrons of energies ranging from 0.4 GeV/$c$ to 4 GeV/$c$ scattered off $^{4}$He, $^{12}$C, $^{56}$Fe and $^{208}$Pb nuclei at four scattering angles ( $15\,^{\circ}$, $60\,^{\circ}$, $90\,^{\circ}$, $120\,^{\circ}$ ) and scattered energies ranging from 0.1 GeV/c to 4 GeV/c. The Rosenbluth method is used to extract the transverse and longitudinal response functions at three-momentum transfers 0.55 GeV/$c$ $\leq \vec {\vert q \vert} \leq$ 1.0 GeV/$c$. Proper Coulomb corrections will be applied. The Coulomb Sum will be determined in the above $\vec {\vert q \vert} $ range and compared to predictions. Progress of data analysis will be presented.