VPE 511: Environment and Environmental Hygiene (2+1)

SAMPLES FOR BACTERIOLOGICAL ANALYSIS

• The samples should be collected in clean sterilised bottles, made of neutral glass with 200-250 ml capacity, provided with glass stopper, with an overlapping ring to avoid contamination.
• If water to be sampled has chlorine, small quantity of sodium thiosulphate (0.1 ml 3% solution or a small crystal) to be added to water sample.
• Sampling bottle should not be opened till it is used for filling sample. Laboratory examination should be started in 24 hours.
• In hot tropics, keep water in ice till analysed (within 48 hours). If not properly preserved, it is not suitable for bacterial examination.
• For bacteriological examination the mouth of tap may be sterilised using a flame gun.