You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is In molecular cloning, Blue-white screening is used for - and explain in detail?
Screening for selecting the cells with vector DNA containing the desired insertional DNA sequence can be done by :


Antibiotic resistance markers:- Allow only cells in which the vector has been transfected to grow.
Blue-white screening:- It is based on lac operon. The hydrolysis of X-gal by β-galactosidase cause blue colour in colonies & indicates that colonies contain the unligated vector. Whereas, white colonies indicate insertion of foreign DNA and loss of cells ability to hydrolyse marker.
PCR, restriction fragment analysis and DNA sequencing:- Confirmatory methods.