Infectious diseases are caused by microorganisms such as viruses, bacteria, fungi or parasites and can spread between individuals. 1  Infectious diseases are caused by microorganisms such as viruses, bacteria, fungi or parasites.2  Microorganisms that cause disease are collectively called pathogens. Many diseases become difficult to control if the infectious agents evolve resistance to commonly used drugs: 2  For example, bacteria can accumulate mutations in their DNA or acquire new genes that allow them to survive contact with antibiotic drugs that would normally kill them.
Southern blot. A Southern blot is a method used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization.
Western blot. A western blot is a laboratory method used to detect specific protein molecules from among a mixture of proteins. This mixture can include all of the proteins associated with a particular tissue or cell type.he first step in a western blot is to prepare the protein sample by mixing it with a detergent called sodium dodecyl sulfate, which makes the proteins unfold into linear chains and coats then with a negative charge.