Final answer:
To verify a plasmid contains a gene of interest, bacteria are grown on antibiotic media and screened using blue-white screening.
Step-by-step explanation:
To check if a plasmid contains a gene of interest, several techniques are used in molecular biology. Typically, after a plasmid is introduced into bacteria through a transformation process, the bacteria are grown on a medium containing an antibiotic like ampicillin. Only bacteria that have taken up the plasmid, which carries an antibiotic resistance gene, will survive.
To ensure the gene of interest is within the plasmid, one commonly used method is blue-white screening. In this technique, the plasmid also contains a lacZ gene that allows for colorimetric identification of recombinant bacteria. Bacteria with disrupted lacZ gene (due to insertion of the gene of interest) form white colonies, while those with the uninterrupted lacZ gene form blue colonies.