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.
Northern Blot Analysis Northern hybridization (RNA blotting) allows us to identify the size and amount of a specific mRNA in a total RNA sample.This technique, in which a labeled probe is hybridized to homologous RNA sequences, is a powerful tool used in order to screen total RNA for the presence of a specific mRNA.orthern Blot Analysis Northern hybridization (RNA blotting) allows us to identify the size and amount of a specific mRNA in a total RNA sample.