Question

You are required to test river water for the presence of bacteria and viruses and to determine their tolerance to heavy metals as well as resistance to antibiotics. Describe in detail various techniques that you would use to achieve these aims.

Answer 1

Tests for water analysis

For bacteria

1) classical methods : MPN (most probable number ), MFMtest (F Membra filter test), P-A test ( presence absence test )

2) Molecular methods :

Immunological methods : ELISA( enzyme-linked immunosorbent assay), IFA ( immunofluorescence assay),

Nucleic acid based method : PCR ( polymerase chain reaction)

For virus

• Plaque forming test , PCR, ELISA, plaque forming test with PCR, NASBA ( nucleic acid sequence based amplification)

For heavy metal tolerance

• agar plate method

• MIC technique ( minimum inhibitory concentration)

For Antibiotic resistant

• Dilution method ( broth and agar dilution method )

• Disk diffusion method

• E-test

• PCR

• DNA hybridization methods