Genetic engineering of human lymphocytes is often carried out via electroporation, a procedure in which an electrical current increases the permeability of the cell membrane and allows cell structures to flow through a cell’s membrane. Although effective at both T cell receptor (TCR) knock-out and chimeric antigen receptor (CAR) knock-in, electroporation can cause cytotoxicity within cells and thus decrease cell viability. Peptide-mediated engineering of human lymphocytes is a proposed alternative form of lymphocyte engineering. Using this process, cells rely on selected peptides to carry out the transfer of genetic material without the use of electrical current. This method of genetic engineering of cells preserves cell viability due to its less destructive nature, yet also often has a lower rate of genetic engineering. Thus, this project aims to determine if electroporation or peptide-mediated engineering of human lymphocytes is a more effective means of performing a TCR knock-out and CAR knock-in. The project ultimately concludes that electroporation is a more efficient means of engineering human lymphocytes due to a higher efficiency of CAR knock-in and similar viability to peptide-mediated cells.