Question: Separations by capillary zone electropheresis (CZE) are characterized in that the electrophoretic medium: 
 Options:  <1> It is always formed by 1.0 M HCl. <2> It is always formed by NH3 1.0 M. <3> It is homogeneous throughout the capillary. <4> It is not homogeneous throughout the capillary. <5> It has a pH gradient throughout the entire capillary.
3