Southern blotting is done for

Production of a human protein in bacteria by genetic engineering is possible because

The steps involved in the Southern blot test are as follows:
$I.$ $X-ray$ film
$II.$ Electrophoresis
$III.$ Digestion with restriction enzyme
$IV.$ Ethidium bromide
$V.$ Radioactive probe
Choose the option having the correct sequential order of these events.

How can purified $DNA$ be precipitated from a solution after appropriate treatment?

$PCR$ is used for:

Which of the following is not present in a bioreactor?