Polymerase chain reaction $\text{(PCR)}$ amplifies $\text{DNA}$ following the equation:

How many types of primers are required for the amplification of a gene in $PCR$?

It is used to detect $HIV$ in suspected $AIDS$ patient and detect mutations in genes in suspected cancer patient too.

Separation and purification by filtration,centrifugation of the desired compound produced in a bioreactor is a part of:

$A$ mixture of fragmented $DNA$ was electrophoresed in an agarose gel. After staining the gel with ethidium bromide,no $DNA$ bands were observed. What could be the reason?

Diagrammatically represent the experimental steps in cloning and expressing a human gene (e.g.,the gene for growth hormone) in a bacterium like $E. coli$.