Kanamycin sulfate is widely used in microbiology and molecular biology as an antibiotic to inhibit the growth of bacteria. It is particularly effective against Gram-negative and some Gram-positive bacteria, making it a valuable tool in selecting and maintaining bacterial cultures that contain antibiotic resistance genes, such as those used in genetic engineering. In laboratory settings, it is often added to agar plates or liquid media to ensure only transformed bacteria with the desired resistance gene grow. Additionally, it is employed in cell culture to prevent bacterial contamination. In human medicine, it is used to treat serious bacterial infections such as urinary tract infections, intra-abdominal infections, and respiratory tract infections, particularly when other antibiotics are ineffective. It is also used in veterinary medicine to treat infections in animals. Furthermore, in agriculture, it is applied to control bacterial plant diseases and as a selectable marker in plant biotechnology. Its broad-spectrum activity and reliability make it a staple in both research and clinical applications.