The following points highlight the top four techniques used for the isolation of microbial mutants. The techniques are: 1. Direct Observation 2. Enrichment Technique 3. Replica-Plating Technique 4. The Ames Test. 1. Direct Observation Technique: In some cases, a colony growing on an agar plate can easily be seen to be different from the normal parental type (wild-type). For example, [...]
The following points highlight the five important types of DNA repair system. The types are: 1. Direct Repair 2. Excision Repair 3. Mismatch Repair 4. Double-Strand Break Repair 5. SOS Repair. Type # 1. Direct Repair: It involves the reversal of DNA damage. (i) Photo-Reactivation: Pyrimidine dinners (induced by UV rays) can be monomerised again by DNA photolyases in presence [...]
The following points highlight the three main stages for mechanism of induced mutagenesis. The stages are: 1. Base Analogue Incorporation 2. Base Alteration 3. Distortion of DNA. Stage # 1. Base Analogue Incorporation: Some chemical compounds are sufficiently similar to the nitrogen bases of DNA so that they occasionally are incorporated into DNA in place of normal bases, such compounds [...]