A method of electroporating cells with a cargo, comprising: flowing the cells with the cargo, preferably a nucleic acid, into an electroporation chamber, wherein the electroporation chamber comprises: a first electrode; a second electrode; a first input allowing passage of the cells and the cargo into the electroporation chamber; a first output allowing passage of electroporated cells from the electroporation chamber; and a fluid channel region having a path defined therein between the first electrode and the second electrode for the cells and the cargo to flow; wherein the cells are suspended in an electroporation medium and have a cell density of about 1×10 6 cells/ml to about 500×10 6 cells/ml; wherein the electroporation medium comprises a metal halide salt, a phosphate salt, a monosaccharide and a buffering agent; and applying multiple electrical pulses to the cells within the electroporation chamber, wherein: (i) each electrical pulse has a form of an exponentially discharging waveform or a square waveform, (ii) the multiple electrical pulses are applied at a field strength of about 0.3 kV/cm to about 3 kV/cm; (iii) the field strength is applied at a voltage of about 15 V to about 100 V; (iv) a time duration between each electrical pulse is about 0.1 seconds to about 10 seconds; and (v) each electrical pulse has a pulse width of about 10 μs to about 10,000 μs. flowing the cells with the cargo, preferably a nucleic acid, into an electroporation chamber, wherein the electroporation chamber comprises: a first electrode; a second electrode; a first input allowing passage of the cells and the cargo into the electroporation chamber; a first output allowing passage of electroporated cells from the electroporation chamber; and a fluid channel region having a path defined therein between the first electrode and the second electrode for the cells and the cargo to flow; wherein the cells are suspended in an electroporation medium and have a cell density of about 1×10 6 cells/ml to about 500×10 6 cells/ml; wherein the electroporation medium comprises a metal halide salt, a phosphate salt, a monosaccharide and a buffering agent; and a first electrode; a second electrode; a first input allowing passage of the cells and the cargo into the electroporation chamber; a first output allowing passage of electroporated cells from the electroporation chamber; and a fluid channel region having a path defined therein between the first electrode and the second electrode for the cells and the cargo to flow; wherein the cells are suspended in an electroporation medium and have a cell density of about 1×10 6 cells/ml to about 500×10 6 cells/ml; wherein the electroporation medium comprises a metal halide salt, a phosphate salt, a monosaccharide and a buffering agent; and applying multiple electrical pulses to the cells within the electroporation chamber, wherein: (i) each electrical pulse has a form of an exponentially discharging waveform or a square waveform, (ii) the multiple electrical pulses are applied at a field strength of about 0.3 kV/cm to about 3 kV/cm; (iii) the field strength is applied at a voltage of about 15 V to about 100 V; (iv) a time duration between each electrical pulse is about 0.1 seconds to about 10 seconds; and (v) each electrical pulse has a pulse width of about 10 μs to about 10,000 μs. (i) each electrical pulse has a form of an exponentially discharging waveform or a square waveform, (ii) the multiple electrical pulses are applied at a field strength of about 0.3 kV/cm to about 3 kV/cm; (iii) the field strength is applied at a voltage of about 15 V to about 100 V; (iv) a time duration between each electrical pulse is about 0.1 seconds to about 10 seconds; and (v) each electrical pulse has a pulse width of about 10 μs to about 10,000 μs.