Question

short and sweet and to the point please

6. Blue-white screening is a method of selecting recombinant bacteria. Explain the screening procedure. Include the following terms: ampicillin-resistant gene, B-galactosidase gene, recombinant plasmid (6 points)

Answer 1

So in the selection of colonies the procedure can be made simple when a vector has selected along with the strain of E. coli which are basically compatible with the Blue- white screening. The strains of E.coli are composed of the lacZ which is actually found when a fragment of B-galactisidase gene is mutated and lost.

The other segment is being referred to as the W- fragment. Now when a plasmid is used which has the portion which is lost called the alpha fragment . So the basic functioning of the beta galactosidase gene can be regenerated when this plasmid is inserted in to the bacterium. In the process of Blue and white screening the plasmids have numerousregions of coding which results in the non functional alpha fragment to get generated

This alpha fragment is non functional and has no role in the alpha complementation

Many experiments were conducted where the multiple cloning sites are inserted into the alpha peptide and this is inserted into the plasmid that results in the alpha complementation cloning vector

Basically there are many markers that are used for the selection and used for the identification of the bactera whih have a particular trait. Generally markers are used that have resistence to antibiotics like that of ampicillin

As Ampicillin restricts the growth of enzymes that allow the process of synthesizing the cell wall, it is most widely used selection marker

This is the most simplified answer. I can still mention many points like the limitations etc.

I hope this helps. Please do let me know if I can help you with anything.

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