Bacterial Transformation: How Foreign DNA Enters Cells
'' Bacterial Transformation: How Foreign DNA Enters Cells" # Introduction Bacterial transformation is the process by which bacteria take up foreign DNA — usually a plasmid — from their environment and stably maintain it inside their cells. This technique lies at the heart of recombinant DNA technology , enabling scientists to clone genes , express proteins , and propagate engineered plasmids . From the early work of Frederick Griffith in 1928 to the modern heat-shock and electroporation methods, transformation has shaped the very foundations of genetic engineering and biotechnology . # H istorical Background The story of bacterial transformation began with a classic experiment by Frederick Griffith (1928) , who discovered that a “transforming principle” from dead virulent Streptococcus pneumoniae could convert harmless bacteria into virulent ones. Later, Oswald Avery, Colin MacLeod, and Maclyn McCarty (1944) demonstrated that this “transforming principle” was...