• In microbiology we often come across this word typing in simplest words means classification of microorganisms
• Typing is broadly classified as
– Phenotypic methods
– Genotypic methods
• Genotypic methods are the ones which analyse the kind of genes present on chromosomes and plasmids of microorganisms. They are used to know whether the genes are homologous or heterologous
• And also to know certain specific genes whether they are present or absent and similar other attributes of the genes . They are way more complicated to do and interpret the results as these are expensive methods , hence they are not used in routine diagnostic purpose.
• phenotypic methods are the commonly used methods. These methods are used for diagnostic purpose. These methods are based on observable characters or physical characters of microorganism like shape, size, results from biochemical reaction, susceptibility or resistance to antibiotics or other certain viruses.
• Common type of phenotypic methods is serotyping. Serotyping refers to sero means surface and typing means classification. Serotyping is based on differences in the different structures decorated on the surface of microorganism.
• Serotyping is based on the surface structures such as lipopolysaccharides,membrane proteins, capsular polysaccharide, fimbriae and flagella.
Reference :- Apurba sastry