When a gene is transferred into the kidney, it might be expressed in the tubular or glomerular regions. To specifically target designated kidney cells for therapeutic reasons, it is advantageous to be able to regulate the transgene’s final destination. Transfection of proximal tubular cells by polyplex infusion into the rat renal artery was recently shown. Fluorescent polyethyleneimine polyplexes with fluorescent poly-L-lysine were created to explore if this mechanism involved glomerular filtration of the DNA-carrying particles. This way, it was possible to see precisely how the particles made their way into the kidney. Since luminous proximal tubules were found in our polyplexes, they were filtered via the glomerulus. DOTAP-containing luminous lipo-polyplexes, on the other hand, were never seen in tubular cells. It was found the mean size of polyplexes was less than lipo0polyplexes (93 nm) via laser light scattering (160 nm). Because of the restrictions given by the glomerular filtration membrane, the diameter of the transfecting particles is an essential element in this process. This knowledge is significant in the context of optimizing gene transcription in tubular cells by manipulating the physical and chemical characteristics of DNA complexes.