What is used for the large-scale production of products in biotechnology?

Describe the role of $CaCl_2$ in the preparation of competent cells.

Which of the following methods are collectively referred to as downstream processing?

$RNA$ is removed by the treatment with

Refer to the following statements for agarose-gel electrophoresis:
$(a)$ The $\text{DNA}$ fragments resolve according to their size.
$(b)$ The separated $\text{DNA}$ fragment can be visualised only after staining with ethidium bromide followed by exposure to $UV$ radiation.
$(c)$ $\text{DNA}$ is always loaded into the well.
$(d)$ The smallest fragment of $\text{DNA}$ is near the well.
Choose the correct statements:

With respect to $DNA$ fragmentation:
Statement $A$: Gel electrophoresis and elution are two important processes.
Statement $B$: After staining with ethidium bromide,it has to be exposed to $UV$ light.