THE MOLECULAR BASIS OF INHERITANCE
CLONING GENES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Isolate recombinant DNA from bacteria
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Identify cell with target DNA to be cut by restriction enzyme
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Identify bacteria with plasmid to be used as vector
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Identify bacteria with recombinant plasmid
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Detailed explanation-1: -A genetic screen or mutagenesis screen is an experimental technique used to identify and select for individuals who possess a phenotype of interest in a mutagenised population. The use of chromogenic substrate to detect a particular enzymatic activity is the basis to screen the desired clone.
Detailed explanation-2: -Plasmids come in many different sizes and are used for many different purposes in biotechnology. They first made their mark in the field of recombinant DNA in the 1970s, being used as a tool to insert genes into bacteria to encourage their production of therapeutic proteins such as human insulin.
Detailed explanation-3: -Blue-white screening is a rapid and efficient technique for the identification of recombinant bacteria. It relies on the activity of -galactosidase, an enzyme occurring in E. coli, which cleaves lactose into glucose and galactose.
Detailed explanation-4: -A widely used method of screening is the blue-white screen, which relies on the lacZ gene. lacZ encodes the enzyme -galactosidase which can hydrolyse lactose. Fortunately, for the lab researcher, when the substrate X-gal is broken down by -galactosidase, it turns into an insoluble blue pigment.