*Many monocyte or macrophage related cell lines such as THP-1, U937, HL-60 and Molm13 will die out within two to three days after plasmid electroporation. These cells have no problem with mRNA, siRNA and Cas9 RNP electroporation. The efficiency would be nearly 100% and cell survival is not affected. Celetrix has developed the THP-1 Helper Kit for plasmid electroporation of monocytic cell lines. A significant portion of THP-1 and U937 cells can survive and grow with the helper kit, enabling easy generation of stable cell lines. Our THP-1 Helper Kit does not help cell lines such as Molm13 and SUP-M2 with plasmid electroporation and we are actively researching the solutions.