The following points highlight the four methods to detect and isolate mutants. The methods are: 1. Replica Plating Technique 2. Resistance Selection Method 3. Substrate Utilization Method 4. Carcinogenicity Test. 1. Replica Plating Technique: Lederberg and Lederberg (1952) have given replica plating technique. This technique is used to detect auxotrophic mutants which differentiates between mutants and wild type strains on [...]
In this article we will discuss about:- 1. Origin of Spontaneous Mutations 2. Evidence for Spontaneous Mutation 3. Random Nature 4. Mutation Rates. Origin of Spontaneous Mutations: Mutation involves changes in DNA. Several mechanisms are known that bring about alterations in DNA. These modifications may arise from error in DNA replication, damage to DNA from radiation. Errors occur during replication [...]
In this article we discuss about the expression of mutations. The expression of mutation can be observed only when there occurs a detectable and altered phenotype. If a mutation occurs from a most prevalent wild type to a mutant form, it is called forward mutation. In forward mutation, a second mutation may take place resulting in appearance of a wild [...]