Write any two biochemical/molecular diagnostic procedures for early detection of viral infection. Explain the principle of any one of them.

OR

Describe the steps that are followed during secondary treatment of sewage.

Two diagnostic procedures are –

•Target Amplification Technique

•PCR ( nucleic acid amplification test)

PRINCIPLE OF PCR

•Amplify ( multiply) a specific nucleic acid sequence,exponentially producing billions of copies

OR

Secondary treatment is a process for wastewater( sewage) to separate and achieve the better quality as much as possible

•It removes around 85% of the organic matter in sewage (by using bacteria in it )

•Principal – the trickling filter and the activated charcoal

•This can be done in three ways –

•BIOFILTRATION - this involves sand filters , contact filters , or trickling filters to remove the additional sediment

Trickling filters are the most effective

•AERATION – it involves the mixing water waste with a solution of micro organism

It is a long (aerated for upto 30 hours) and effective process

•OXIDATION PONDS – it involves the natural water bodies such as lagoons

Water waste is passed through this body for a period of time and then retained for 2-3 weeks